Fastened assembly body, connector, and hydraulic cylinder unit

ABSTRACT

In a connection surface ( 3   c ) of each of two members ( 1   a,    1   b ) to be fastened, a communication groove ( 6 ) opened on a surface and an engagement groove ( 7 ) communicating therewith, being wider than the communication groove ( 6 ), and provided with a connection surface ( 9 ) parallel to the connection surface ( 3   c ) are formed. A fastener ( 8 ) includes: two engaging pieces ( 11 ), which can be inserted into the engagement grooves ( 7 ) and are wider than the communication grooves ( 6 ) and are provided with fastening surfaces ( 15 ); and a connecting portion ( 14 ) therebetween, wherein the entirety of the fastener ( 8 ) can be inserted into the interior of one set of communication groove ( 6 ) and engagement groove ( 7 ), which are opposed to and communicate with each other, by thrusting the respective engaging pieces ( 11 ) and connecting portion ( 14 ) thereto. In the inserted state, fastening surfaces ( 15 ) of the respective engaging pieces ( 11 ) contact with engagement surfaces ( 9 ) of the engagement grooves ( 7 ), thereby being unable to be pulled out in a direction orthogonal to the connection surfaces ( 3   c ) of the two members ( 1   a,    1   b ). That is, the two members ( 1   a,    1   b ) have nothing protruding from a surface by virtue of the fastening assembly, and are in a firmly fastened state via the fastener ( 8 ).

TECHNICAL FIELD

The present invention relates to a fastening assembly and a fastener forfastening two members to each other, and to a fluid pressure cylinderunit fastened and assembled with an attachment by the fastener assemblyand the fastener.

BACKGROUND ART

Conventionally, a fastening means for attachably and detachably couplinga plurality of members or parts to one another includes mainly afastening metal-fitting such as a bolt having a screw, or a pin orcotter utilizing a wedge action, elasticity, or friction.

Also, a fastening means other than one employing the above-describedfastening metal-fitting includes, for example, as described in JapanesePatent Laid-Open Publication No. 8-128420, a structure in which: aT-slot is formed in each of connection surfaces of two members to befastened; a linking member, in which a pair of protrusions and a pair ofelastic protrusions are symmetrically formed on a center wall regardedas a center, is used; the protrusion and the elastic protrusion on eachside are inserted into the respective T-slots in a direction almostorthogonal to a connection surface and are engaged inside; and the twomembers are engaged inside and fastened.

One utilization example of the fastening assembly assembled by theabove-described fastening means includes a fluid pressure cylinder unitconstituting a cylinder tube fastened to an attachment. This fluidpressure cylinder unit can increase a driving force or stroke as anactuator by fastening and assembling a plurality of fluid pressurecylinders to one another, or improve rigidity and actuation accuracy ofthe entirety by fastening an attachment, such as a guide unit providedwith a guide rod for supporting a piston rod, to a fluid pressurecylinder.

In many cases, the cylinder tube serving as a body of the fluid pressurecylinder and an attachment body are members having comparatively largeweight and are mutually subjected to reaction forces of the rod duringactuation. Therefore, the cylinder tube and the attachment in the fluidpressure cylinder must be certainly fastened, so that such a fasteningmeans includes utilizing a structure in which interior engagement iscarried out mutually via the above-described fastening metal-fittingsuch as a bolt or the above-described linking member.

However, in a fastening structure using the fastening metal-fitting suchas a bolt, a large-volume bracket must be interposed on a surface of aconstituent member to be fastened. Or, in the case of using the bolt,its head protrudes from a member surface. These are large factors forhindering a space from being saved since the space for installing eachmember is limited depending on recent device downsizing.

Meanwhile, in a fastening structure in which the interior engagement iscarried out via the linking member, since there is nothing protrudingfrom a surface of the member such as the head of the bolt even in afastened state, this structure is suitable for saving the installationspace. Further, mutual relative arrangements or fastening locations oftwo members can be arbitrarily set and changed since providing a screwhole or pin hole is not required. However, even if each of theprotrusion and the elastic protrusion on each side is inserted into theT-shaped groove in a direction almost orthogonal to their connectionsurface, they can be easily separated by being detached in an oppositedirection and therefore it is difficult to fasten them firmly.

An object of the present invention is to provide a fastening assemblyand a fastener which are suitable for saving the installation space,capable of arbitrarily and easily setting the mutual relativearrangements and fastening positions of the respective members, andcapable of firmly fastening them.

Another object of the present invention is to provide a fluid pressurecylinder unit having various structures in each of which there isnothing protruding from the surfaces while cylinder tubes are firmlyfastened to each other.

Another object of the present invention is to provide a fluid pressurecylinder unit in which an arbitrary fluid pressure cylinder is combinedwith an arbitrary attachment so as to be fastened easily and firmly.

DISCLOSURE OF THE INVENTION

A fastening assembly according to the present invention comprises: twomembers, on each of which a connection surface is formed and which acommunication groove extending and opened in a longitudinal directionalong each of said connection surfaces, and an engagement grooveprovided with an engagement surface parallel with each of saidconnection surfaces and communicating with said communication groove areformed; and a fastener including, in a state in which said communicationgrooves are opposed to each other and said two members are made tocontact through each of said connection surfaces, a first engaging piecewhose fastening surface is formed in the longitudinal direction andwhich is inserted into said engagement groove of one of said members inthe longitudinal direction, a second engaging piece whose fasteningsurface is opposed to said fastening surface and formed in thelongitudinal direction and which is inserted into said engagement grooveof the other of said members in the longitudinal direction, and aconnecting portion which has a width smaller than those of said engagingpieces and at whose base end each of the engaging pieces are connected,wherein when said fastener is embedded in said two members and saidengagement surfaces and said fastening surfaces contact with each other,said two members are connected.

The fastening assembly according to the preset invention is such thatsaid engagement grooves, said first engaging piece, and said secondengaging piece are formed to become wider than said communicationgroove.

The fastening assembly according to the present invention is such thatsaid fastener is an intermediate fastener which is installed at alongitudinal-directional middle position of said communication grooveand said engagement groove.

The fastening assembly according to the present invention is such thatsaid connecting portion is formed into a cylindrical shape with adiameter capable of being inserted into said communication groove, and awidth in a state in which at least one of said first engaging piece andsaid second engaging piece is rotated about a central axis of saidconnecting portion by a predetermined angle is formed smaller than thewidth of said communication groove.

A fastener according to the present invention is one for fastening twomembers and comprises: a first engaging piece whose fastening surface isformed in a longitudinal direction; a second engaging piece whosefastening surface is opposed to said fastening surface and formed in thelongitudinal direction; a connecting portion having a width smaller thanthose of said engaging pieces and connecting the engaging pieces at abase end; and a fastening member for elastically deforming tips of saidengaging pieces in a direction in which the respective fasteningsurfaces approach each other.

The fastener according to present invention is such that said fasteningmember is a screw member, which penetrates an outer surface parallel tosaid fastening surfaces and a tip face of said engaging piece, so as tobe screw-connected to a screw hole formed in said engaging piece.

The fastener according to the present invention further comprises acut-in portion formed for dividing respective tips of said engagingpieces into an outer elastically deformable portion and an innerelastically deformable portion, wherein said fastening portion is ascrew member to be screwed into a screw hole formed between said outerelastically deformable portion and said inner elastically deformableportion.

The fastener according to the present invention is such that saidfastening member is formed by a fastening piece in which an abuttingface abutting on an abutting face formed to be inclined is formed ateach tip of said engaging pieces and by a screw member to bescrew-connected to a screw hole formed in said fastening piece, througha through hole formed in said connecting portion.

A fastener according to the present invention is one for connecting twomembers and comprises: a first engaging piece integrally provided with afirst connecting portion, and having a fastening surface wider than saidfirst connecting portion and formed in a longitudinal direction and anabutting face formed so as to be inclined at a tip thereof; a secondengaging piece integrally provided with a second connecting portion, andhaving a fastening surface wider than said second connecting portion andshifted in the longitudinal direction from and mutually opposed to saidfastening surface and formed in the longitudinal direction, and a secondengaging piece having an abutting face abutting on said abutting faceand formed at a tip thereof; and a screw member screw-connected to ascrew hole formed in one of said engaging pieces, penetrating a throughhole formed in the other of said engaging piece with a diameter largerthan that of said screw hole, and making said engaging pieces move alongsaid abutting face in a direction in which the respective fasteningsurfaces approach each other.

In the fastening assembly and the fastener of the present invention, thecommunication groove and the engagement groove having the engagementsurface are formed in each of the connection surfaces of the twofastened members, so that the entirety of the fastener can be insertedinto their interiors in a state of being opposed to and completelycommunicating with each other. In this inserted state, since thefastening surfaces of the engaging pieces contact and are engagedrespectively with the engagement surfaces, they are not removed from theconnection surfaces of the members in the direction orthogonal thereto.Therefore, the two members cannot be separated from each other via thefastener, that is, the two members can obtain a firmly fastened state sothat there is nothing protruding from the surfaces thereof. In the twomembers, the relative arrangements and the positions to be fastened canbe arbitrarily and easily set and changed.

A fluid pressure cylinder unit according to the present invention is onefor driving an object to be driven in a straight-line direction by afluid pressure and comprises: a cylinder tube, in which a communicationgroove extending and opened in a longitudinal direction along aconnection surface and an engagement groove provided with an engagementsurface parallel to said connection surface and communicating with saidcommunication groove are formed and a piston provided with a piston rodis accommodated axially and reciprocably; an attachment, in which acommunication groove extending and opened in the longitudinal directionalong a connection surface contacting with said connection surface andan engagement groove provided with an engagement surface parallel tosaid connection surface and communicating with said communication grooveare formed; and a fastener including, in a state in which saidcommunication grooves are opposed to each other and said cylinder tubeand said attachment are made to contact by said connection surfaces, afirst engaging piece whose fastening surface is formed in thelongitudinal direction and which is inserted into said engagement grooveof said cylinder tube in the longitudinal direction, a second engagingpiece whose fastening surface is opposed to said fastening surface andformed in the longitudinal direction and which is inserted into saidengagement groove of said attachment in the longitudinal direction, anda connecting portion having a width smaller than those of said engagingpieces and connecting each of said engaging pieces at a base endthereof, wherein when said fastener is embedded in said cylinder tubeand said attachment and said engagement surfaces and said fasteningsurfaces contact with one another, said cylinder tube and saidattachment are connected.

The fluid pressure cylinder unit according to the present inventionfurther comprises a fastening member for elastically deforming tips ofsaid engaging pieces in a direction in which the respective fasteningsurfaces approach each other.

The fluid pressure cylinder unit according to the present invention issuch that a transverse section of said cylinder tube is a quadrangle,and respective mutually adjacent outer circumferential surfaces thereofserve as connection surfaces in which said communication grooves areformed.

The fluid pressure cylinder unit according to the present invention issuch that said attachment is a cylinder tube similar to said cylindertube.

The fluid pressure cylinder unit according to the present invention issuch that a piston rod of said cylinder tube and a piston rod of saidattachment are connected by a connecting member.

The fluid pressure cylinder unit according to the present invention issuch that said two cylinder tubes are fastened so that respective pistonrods thereof are directed in reverse to each other, and a chuck memberis attached to each of said piston rods.

The fluid pressure cylinder unit according to the present invention issuch that a guide rail is attached to each of said cylinder tubes, and aslide table attached to a sliding body which slides along said guiderail is connected to each of said piston rods.

The fluid pressure cylinder unit according to the present invention issuch that said attachment serves as a guide block for axiallyaccommodating a guide rod reciprocably, and said guide rod and saidpiston rod are connected by a connecting member.

The fluid pressure cylinder unit according to the present invention issuch that a plurality of said cylinder tubes and a plurality of saidattachments are fastened, respectively.

In the fluid pressure cylinder unit of the present invention, since thefluid pressure cylinder and the attachment can be firmly fastenedwithout anything protruding therefrom, the above is the structuresuitable for saving the installation space. Concurrently, since thefluid pressure cylinder, guide unit, and spacer block, etc. can beeasily and certainly fastened mutually, a cylinder unit of, for example,a single or double guide-attached cylinder, a lifter cylinder, an airchuck, or a double-stroke cylinder can be easily assembled. Further, inthe two cylinder tubes, since the relative arrangements and thepositions to be fastened can be arbitrarily and easily set and changed,the fastening can be easily obtained by combining an arbitrary fluidpressure cylinder with an arbitrary guide unit.

A fluid pressure cylinder unit according to the present invention is oneemploying a rodless cylinder for driving a reciprocating body in astraight-line direction by fluid pressure and comprises: a casing of therodless cylinder in which a piston reciprocated in the straight-linedirection by the fluid pressure and connected to said reciprocating bodyis incorporated and in which a communication groove extending and openedalong a connection surface formed at an outer periphery and anengagement groove communicating with said communication groove and beingwider than said communication groove are formed; an attachment in whicha communication groove extending and opened along a connection surfacecontacting with said connection surface and an engagement groovecommunicating with said communication groove and being wider than saidcommunication groove are formed; and a fastener including, in a state inwhich the respective communication grooves are opposed to each other andsaid casing and said attachment are made to contact respectively by saidconnection surfaces, a first engaging piece inserted into saidengagement groove of said casing in a longitudinal direction, a secondengaging piece inserted into said engagement groove of said attachmentin the longitudinal direction, and a connecting portion for connectingthose engaging pieces, the fastener being embedded in said casing andsaid attachment.

The fluid pressure cylinder unit according to the present inventionfurther comprises a fastening member provided to said fastener forapplying a fastening force to said casing and said attachment via saidfastener.

The fluid pressure cylinder unit according to the present inventionfurther comprises: a piston yoke protruding, through a slit formed in areciprocation guide surface formed in said casing, outwardly from saidreciprocation guide surface and connecting said piston and saidreciprocating body; an inner sealing band fixed to both ends of saidcasing and sealing said slit from inside; and an outer sealing bandfixed to the both ends of said casing and sealing said slit fromoutside.

The fluid pressure cylinder unit according to the present invention issuch that said attachment is a guide member provided with a rail forguiding said table. Further, guide members are fastened on both sides ofthe casing of said rodless cylinder.

The fluid pressure cylinder unit according to the present invention issuch that said attachment is a casing of a rodless cylinder of the sametype as that of said casing.

In the fluid pressure cylinder unit of the present invention, since thecasing of the rodless cylinder and the adjacent attachment can be firmlyfastened without anything protruding therefrom, this is suitable forsaving the installation space and the rigidity of the rodless cylindercan be enhanced. The attaching position of the fastener to the casingcan be arbitrarily set by being moved along the engagement groove. Ifthe attachment is a guide member, the reciprocating body can be movedwith higher accuracy by guiding through the guide member thereciprocating body that is driven by the rodless cylinder.

A fluid pressure cylinder unit according to the present invention is onefor driving an object to be driven in a straight-line direction by fluidpressure and comprises: a cylinder tube for accommodating a piston; apiston rod attached to said piston and protruding from an end face ofsaid cylinder tube to outside; and a rod cover mounted attachably anddetachably on the end face of said cylinder tube, wherein said rod coveris provided with a functional component exhibiting a functional effectin accordance with a use application.

The fluid pressure cylinder unit according to the present invention issuch that a communication groove extending and opened in a longitudinaldirection along a connection surface and an engagement groove providedwith an engagement surface parallel to said connection surface andcommunicating with said communication groove are formed in saidcylindrical tube, there are included: an attachment in which acommunication groove extending and opened in the longitudinal directionalong a connection surface contacting with said connection surface andan engagement groove having an engagement surface parallel to saidconnection surface and communicating with said communication groove areformed; and, a fastener provided with, in a state in which therespective communication grooves are opposed to each other and saidcylinder tube and said attachment are made to contact respectively bysaid connection surfaces, a first engaging piece whose fastening surfaceis formed in the longitudinal direction and which is inserted into saidengagement groove of said cylinder tube in the longitudinal direction, asecond engaging piece whose fastening surface is opposed to saidfastening surface and is formed in the longitudinal direction and whichis inserted into said engagement groove of said attachment in thelongitudinal direction, and a connecting portion having a width smallerthan those of said engaging pieces and connecting the respectiveengaging pieces at a base end thereof, and when said fastener isembedded in said cylinder tube and said attachment and said engagementsurfaces and said fastening surfaces are made to contact with oneanother, said cylinder tube and said attachment are connected.

The fluid pressure cylinder unit according to the present invention issuch that said functional component is a discharge passage, which isconnected to a discharge port formed in said rod cover and discharges,to the outside, a dust generated by linear reciprocation of said pistonin said fluid pressure cylinder unit.

The fluid pressure cylinder unit according to the present invention issuch that said functional component is an oil-impregnated bearingincorporated in said rod cover and contacting with an outercircumferential surface of said piston rod.

The fluid pressure cylinder unit according to the present invention issuch that said functional component is a linear ball bearingincorporated in said rod cover, contacting with a outer circumferentialsurface of said piston rod, and having a ball for guidingaxial-directional movement of said piston rod.

The fluid pressure cylinder unit according to the present invention issuch that said functional component is an assembly for strokeadjustment, which has a stopper incorporated in said rod cover andrestricting a stroke end position of said piston by contacting with saidpiston and a position adjustment member attached to said rod cover andadjusting a position of said stopper.

The fluid pressure cylinder unit according to the present invention issuch that any of a rod cover for discharging dusts provided with saiddischarging passage, a rod cover for oil-impregnated bearing providedwith said oil-impregnated bearing, a linear-ball-bearing rod coverprovided with said linear ball bearing, and a rod cover for strokeadjustment provided with said assembly for stroke adjustment can beattached to the end face of said cylinder tube.

In the fluid pressure cylinder unit of the present invention, the fluidpressure cylinder employed therein can selectively attach, in accordancewith the use application, a rod cover provided with the functionalcomponent such as a dust discharge passage, an oil-impregnated bearing,a ball bearing, or an assembly for stroke adjustment to the basiccylinder provided in common as a main body driving unit. Therefore, thestructure capable of being applied to various uses and exhibiting highversatility can be attained.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows two blocks fastened as a fastening assembly according to afirst embodiment of the present invention, wherein FIG. 1A is aperspective view thereof, FIG. 1B is a front view thereof, and FIG. 1Cis a side view thereof.

FIG. 2 is a perspective view of an entirety of an insertion fastener.

FIG. 3 shows a structure in which mutual parallel-disposed side faces oftwo contacting blocks are fastened via an I-shaped metal-fitting bybolts, wherein FIG. 3A is a front view thereof and FIG. 3B is a sideview thereof.

FIG. 4 shows a structure in which a connection surface and an end faceof two contacting blocks are joined via an L-shaped metal-fitting bybolts, wherein FIG. 4A is a front view thereof and FIG. 4B is a sideview thereof.

FIG. 5 shows an inclined fastening metal-fitting serving as a fasteneremployed in a fastening assembly according to a second embodiment,wherein FIG. 5A is a perspective view of an entirety thereof, FIG. 5B isa front view of a state in which the inclined fastening metal-fitting isinserted into one set of communication groove and engagement groovewhich are opposed to each other, and FIG. 5C is an insertion-directionalcross-sectional view taken along line 5C-5C of FIG. 5B.

FIG. 6 shows an inclined fastening metal-fitting and a positioning plateused for it, wherein FIG. 6A is a perspective view of an entiretythereof, FIG. 6B is a front view of a state in which the positioningplate is fitted in the set of communication groove and engagement groovewhich are opposed to each other and the inclined fastening metal-fittingis inserted thereto, and FIG. 6C is an insertion-directionalcross-sectional view taken along line 6C-6C of FIG. 6B.

FIG. 7 shows an enlarging divided metal-fitting which is a fastener usedin a fastening assembly according to a third embodiment, wherein FIG. 7Ais a perspective view of an entirety thereof, FIG. 7B is a front view ofthe enlarging divided metal-fitting installed in each interior of theset of communication groove and engagement groove which are opposed toeach other, and FIG. 7C is an insertion-directional cross-sectional viewtaken along line 7C-7C of FIG. 7B.

FIG. 8 shows a modification example of the enlarging dividedmetal-fitting shown in FIG. 7, wherein FIG. 8A is a perspective view ofan entirety thereof, FIG. 8B is a front view of the enlarging dividedmetal-fitting that is the modification example installed in eachinterior of the set of communication groove and engagement groove whichare opposed to each other, and FIG. 8C is an insertion-directionalcross-sectional view taken along line 8C-8C of FIG. 8B.

FIG. 9 shows a wedge dividing metal-fitting which is a fastener used ina fastening assembly according to a fourth embodiment, wherein FIG. 9Ais a perspective view of an entirety thereof, FIG. 9B is a front view ofthe wedge dividing metal-fitting installed in a fastened state in eachinterior of the set of communication groove and engagement groove whichare opposed to each other, FIG. 9C is a cross-sectional view taken alongline 9C-9C in FIG. 9D, and FIG. 9D is an insertion-directionalcross-sectional view taken along line 9D-9D of FIG. 9B.

FIG. 10 shows an inclined dividing metal-fitting which is a fastenerused in a fastening assembly according to a fifth embodiment, whereinFIG. 10A is a perspective view of an entirety thereof, FIG. 10B is afront view of the inclined dividing metal-fitting installed in thefastened state in each interior of the set of communication groove andengagement groove which are opposed to each other, FIG. 10C is across-sectional view taken along line 10C-10C in FIG. 10D, and FIG. 10Dis an insertion-directional cross-sectional view taken along line10D-10D of FIG. 10B.

FIG. 11 shows an H-shaped metal-fitting which is a fastener used in afastening assembly according to a sixth embodiment, wherein FIG. 11A isa perspective view of an entirety thereof and FIG. 11B is a frontcross-sectional view of the H-shaped metal-fitting which is installed inthe fastened state in each interior of the set of communication grooveand engagement groove which are opposed to each other.

FIG. 12 shows a flat inclination H-shaped metal-fitting which is a firstmodification example of an intermediate fastener, wherein FIG. 12A is aperspective view of an entirety thereof, FIG. 12B is a frontcross-sectional view taken along line 12B-12B of FIG. 12C for the flatinclination H-shaped metal-fitting installed in each interior of the setof communication groove and engagement groove which are opposed to eachother, and FIG. 12C is a plane cross-sectional view taken along line12C-12C of FIG. 12B.

FIG. 13 shows a flat round H-shaped metal-fitting which is a secondmodification example of the intermediate fastener, wherein FIG. 13A is aperspective view of an entirety thereof, FIG. 13B is a frontcross-sectional view taken along line 13B-13B of FIG. 13C for the flatround H-shaped metal-fitting installed in each interior of the set ofcommunication groove and engagement groove which are opposed to eachother, and FIG. 13C is a plane cross-sectional view taken along line13C-13C of FIG. 13B.

FIG. 14 is a perspective view showing a stacking valve fastened to amanifold by the fastening assembly according to the first embodiment.

FIG. 15 is a perspective view showing two fluid pressure cylindersfastened by the fastening assembly according to the first embodiment.

FIG. 16 is a perspective view of an entirety of a fluid pressurecylinder unit according to a first embodiment, wherein FIG. 16A is aperspective view showing a before-assembly state and FIG. 16B is aperspective view showing an assembled state.

FIG. 17 is a perspective view of an entirety of a pneumatic cylinderunit according to a second embodiment, wherein FIG. 17A is a perspectiveview showing a before-assembly state and FIG. 17B is a perspective viewshowing: an assembled state.

FIG. 18 is a perspective view of an entirety of a pneumatic cylinderunit according to a third embodiment, wherein FIG. 18A is a perspectiveview showing a before-assembly state and FIG. 18B is a perspective viewshowing an assembled state.

FIG. 19 is a perspective view of an entirety of a pneumatic cylinderunit according to a fourth embodiment, wherein FIG. 19A is a perspectiveview showing a before-assembly state and FIG. 19B is a perspective viewshowing an assembled state.

FIG. 20 is a perspective view of an entirety of a pneumatic cylinderunit according to a fifth embodiment, wherein FIG. 20A is a perspectiveview showing a before-assembly state and FIG. 20B is a perspective viewshowing an assembled state.

FIG. 21 is a perspective view of an entirety of a table-attached singleguide cylinder.

FIG. 22 is a perspective view of an entirety of a pneumatic cylinderunit according to a sixth embodiment, wherein FIG. 22A is a perspectiveview showing a before-assembly state and FIG. 22B is a perspective viewshowing an assembled state.

FIG. 23 is a perspective view of an entirety of a pneumatic cylinderunit according to a seventh embodiment, wherein FIG. 23A is aperspective view showing a before-assembly state and FIG. 23B is aperspective view showing an assembled state.

FIG. 24 is a perspective view of an entirety of a modification exampleof a spacer block.

FIG. 25 is a perspective view of an entirety of a pneumatic cylinderunit according to an eighth embodiment, wherein FIG. 25A is aperspective view showing a before-assembly state and FIG. 25B is aperspective view showing an assembled state.

FIG. 26 is a perspective view of an entirety of a pneumatic cylinderunit according to a ninth embodiment, wherein FIG. 26A is a perspectiveview showing a before-assembly state and FIG. 26B is a perspective viewshowing an assembled state.

FIG. 27 is a perspective view showing an entirety of a pneumaticcylinder unit employing a rodless cylinder according to a tenthembodiment.

FIG. 28 is an exploded perspective view of FIG. 27.

FIG. 29 is a partially-omitted vertical cross-sectional view showing therodless cylinder shown in FIG. 27.

FIG. 30 is a transverse cross-sectional view of FIG. 29.

FIG. 31 is a perspective view showing a pneumatic cylinder unitemploying a rodless cylinder, which is a modification example of thetenth embodiment.

FIG. 32 is a perspective view of an entirety of a pneumatic cylinderused in a pneumatic cylinder unit according to an eleventh embodiment,wherein FIG. 32A is a perspective view showing an exploded state beforeassembling and FIG. 32B is a perspective view showing an assembledstate.

FIG. 33 is an axial-directional cross-sectional view taken along lineA-A of the fluid pressure cylinder assembled in FIG. 32B.

FIG. 34 is a perspective view of an entirety of the pneumatic cylinderunit according to the eleventh embodiment, wherein FIG. 34A is aperspective view showing an exploded state before assembling and FIG.34B is a perspective view showing an assembled state.

FIG. 35 is a perspective view of an entirety of a pneumatic cylinderused in a pneumatic cylinder unit according to a twelfth embodiment,wherein FIG. 35A is a perspective view showing an exploded state beforeassembling and FIG. 35B is a perspective view showing an assembledstate.

FIG. 36 is an axial-directional cross-sectional view taken along lineB-B of the pneumatic cylinder assembled in FIG. 35B.

FIG. 37 is a perspective view of an entirety of a pneumatic cylinderused in a pneumatic cylinder unit according to a thirteenth embodiment,wherein FIG. 37A is a perspective view showing an exploded state beforeassembling and FIG. 37B is a perspective view showing an assembledstate.

FIG. 38 is an axial-directional cross-sectional view taken along lineC-C of the pneumatic cylinder assembled in FIG. 37B.

FIG. 39 is a perspective view of an entirety of a pneumatic cylinderused in a pneumatic cylinder unit according to a fourteenth embodiment,wherein FIG. 39A is a perspective view showing an exploded state beforeassembling and FIG. 39B is a perspective view showing an assembledstate.

FIG. 40 is an axial-directional cross-sectional view taken along lineD-D of the pneumatic cylinder assembled in FIG. 39B, wherein FIG. 40A isa cross-sectional view showing a state in which a movable stopper is atan extendable limit position and FIG. 40B is a cross-sectional viewshowing a state in which the movable stopper is at a retractable limitposition.

FIG. 41 is an axial-directional cross-sectional view of a modificationexample of the pneumatic cylinder used in the pneumatic cylinder unitaccording to the fourteenth embodiment.

FIG. 42 is a front view of an example of a fastening assembly in whichan engagement groove has a polygonal section.

FIG. 43 is a front view of an example of a fastening assembly in whichthe engagement groove has a half-circular section.

FIG. 44 is a front view of an example of a fastening assembly in whichan engagement surface is not parallel to a connection surface.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described indetail with reference to drawings.

First, embodiments of a fastening assembly and a fastener will beexplained. FIG. 1A is a perspective view showing two blocks fastened asa fastening assembly according to a first embodiment of the presentinvention, FIG. 1B is a front view of the two blocks, and FIG. 1C is aside view thereof. As shown in FIG. 1, blocks 1 a and 1 b which are twomembers to be fastened are fastened at positions shifted in alongitudinal direction and in a state of contacting with each other.

Each of the blocks 1 a and 1 b, whose end faces 2 are regular tetragons,is formed into a cuboid, wherein a communication groove 6 opened andextending in the longitudinal direction and an engagement groove 7communicating with it are formed in each of four side faces 3 thereofand wherein the communication groove 6 and the engagement groove 7 ineach of connection surfaces 3 c, which contact with each other, arefastened via an insertion fastener 8 serving as a fastener. Theinsertion fastener 8 becomes in a state in which an entirety of theinsertion fastener 8 is inserted into and installed in an interior inwhich the communication groove 6 and the engagement groove 7 formed ineach connection surface 3 c communicate with each other. In each of theblocks 1 a and 1 b shown in FIG. 1, the communication groove 6 and theengagement groove 7 are formed in each of the four side faces 3.However, the communication groove 6 and the engagement groove 7 may beformed in at least the connection surface 3 c of each of the blocks 1 aand 1 b. Also, although the end faces 2 of the blocks 1 a and 1 b areregular tetragons, they may be rectangles.

As shown in the Figure, the communication groove 6 is formed so as toextend along the side face in the longitudinal direction and be opened,and the engagement groove 7 is formed in each interior of the blocks 1 aand 1 b so as to continue into the communication groove 6, whereby theentirety thereof is formed into a substantially T-shaped section. Thecommunication groove 6 is formed so that its opening width is “Wo” andits opening depth from a surface is “Do”. The engagement groove 7 isformed so that its inner width, which is larger than the opening width“Wo”, is “Wi” and its inner depth is “Di”. Therefore, side faces, whichare disposed on both sides of the communication groove 6 and among innerfaces of the engagement groove and arranged to be parallel to theconnection surfaces 3 c, constitute engagement faces 9.

FIG. 2 is a perspective view of the entirety of the insertion fastener.Note that an upper-right direction of the Figure is a direction of beingthrust into the interiors of the communication groove 6 and theengagement groove 7 in insertion direction of the insertion fastener 8and an opposite lower-left direction is a direction of being pulled out,wherein their directions will be hereinafter referred to as a “thrustdirection” and a “pull direction” for convenience of explanations,respectively.

As shown in FIG. 2, the insertion fastener 8, in which two engagingpieces 11 are disposed symmetrically in a vertical direction of theFigure and a connecting portion 14 is integrally connected between theengaging pieces 11, is a molded product made of a resin, and is aninsertion fastener with the most fundamental structure. Since one of theengaging pieces 11 and the connecting portion 14 are integrally formed,a sectional shape orthogonal to the insertion direction becomes aT-shaped section (see FIG. 1B). The connecting portion 14 is formed sothat its linking width “Wc” is almost equal to or smaller than theopening width “Wo” in order to pierce the communication groove 6. Alinking height “Hc” (i.e., length between the two engaging pieces 11) ofthe connecting portion 14 is formed with a dimension approximately twicelarger than the opening depth “Do” of the communication groove 6.

Side faces formed in the longitudinal direction on both sides of theconnecting portion 14 among outer surfaces of the engagement pieces 11constitute fastening surfaces 15. An engagement width “Wf” of theengaging pieces 11 is larger than the opening width “Wo” so that thefastening surfaces 15 can be contacted and engaged with the engagementfaces 9 of the engagement grooves 7 and the engagement width “Wf” of theengaging pieces 11 is formed to be almost equal to or smaller than theinner width “Wi” so as to be inserted into the engagement groove 7. Anengagement height “Hf” is formed with a dimension almost equal to orsmaller than the inner depth “Di” for being inserted into the engagementgroove 7. The entirety of the insertion fastener 8 having theabove-described structure can be inserted into the interiors of one setof communication groove 6 and engagement groove 7, which are opposed toand communicate with each other as shown in FIG. 1, by being thrust inthe insertion direction.

In such a inserted state, the fastening surfaces 15 of the respectiveengaging pieces 11 contact with the engagement surfaces 9 of theengagement grooves 7, so that the fastening surface 15 cannot be removedfrom the connection surfaces 3 c of the blocks 1 a and 1 b in thedirection orthogonal thereto. Therefore, the two blocks 1 a and 1 bcannot be separated from each other through the insertion fastener 8,i.e., the two blocks 1 a and 1 b are firmly fastened to each other viathe insertion fastener 8. If each dimension of members constituting theinsertion fastener 8 is formed with high accuracy, the two blocks 1 aand 1 b can be satisfactorily certainly fastened. If they are formedwithin dimensional tolerances of a tight fit, prevention of extractionand deviation after inserting can be achieved.

FIG. 3A is a front view of a structure, as a comparative example, inwhich the side faces 3 disposed to be parallel to each other on the twoblocks 1 a and 1 b contacting under the same positional relationship asthat of FIG. 1 are fastened by bolts via an I-shaped metal-fitting 81,and FIG. 3B is a side view thereof. FIG. 4A is a front view of astructure in which the connection surfaces 3 c and the end faces 2 ofthe two blocks 1 a and 1 b contacting with each other are coupled bybolts via an L-shaped metal-fitting 82, and FIG. 4B is a side viewthereof. A screw hole 84 is provided in an insertion engaging member 83capable of being inserted into the engagement groove 7. When bolt screws85 attached thereto are fastened, heads 86 of the bolt screws and theinsertion engaging members 83 strongly clamp and fix the I-shapedmetal-fitting 81 or L-shaped metal-fitting 82 and the communicationgrooves 6 therebetween.

Even in the case of either structures of FIG. 3 and FIG. 4, thethicknesses of the I-shaped metal-fitting 81 or L-shaped metal-fitting82 and the heads 86 of the bolt screws are exposed from the surfaces ofthe blocks 1 a and 1 b, whereby if the entire assembly is installed intoan interior of a device etc., an installation space corresponding to thevolume of the exposed thicknesses is required. A problem is such that,particularly, when the blocks 1 a and 1 b constitute a part of a movablebody, such exposed thicknesses contact with other members, andelectrical wirings, etc.

In contrast, the two blocks 1 a and 1 b in a state of being fastened bythe fastening assembly according to the present embodiment shown in FIG.1 have a structure in which the insertion fastener 8 serving as afastener is disposed in the interior thereof and there is nothingprotruding from the surfaces of the blocks 1 a and 1 b in spite of beingin the fastened state. Therefore, the fastening assembly according tothe present embodiment has a fastening structure suitable for saving theinstallation space required depending on the recent device downsizing.

In addition, if the communication grooves 6 and the engagement grooves 7provided in an elongated manner in the two blocks 1 a and 1 b are eachin a state of partially being opposed to and communicating with eachother, the insertion fastener 8 can be inserted into and fastened insuch a communicating portion. Therefore, even when the relativearrangements of the two blocks 1 a and 1 b are arbitrarily changed in adirection of forming the communication grooves 6, the insertion fastener8 can be inserted therein and fastened thereto. Further, only oneinsertion fastener 8 is inserted in FIG. 1. However, if a range in whichthe communication grooves 6 are mutually communicated is sufficientlylarger, the insertion fastener 8 can be inserted not only into openingsformed at two positions of both ends of the communicating range but alsointo arbitrary positions within the communicating range. Therefore,fastening locations can be also set at arbitrary positions. Theinsertion fastener 8 shown in FIG. 2 is made of a resin, and may be madeof metal.

FIG. 5A is a perspective view of an entirety of an inclined fasteningmetal-fitting which is a fastener used in a fastening assembly accordingto a second embodiment, FIG. 5B is a front view of a state of insertingthe inclined fastening metal-fitting into one set of communicationgroove 6 and engagement groove 7 which are opposed to each othersimilarly to that of the above-described first embodiment, and FIG. 5Cis an insertion-directional cross-sectional view taken along line 5C-5Cof FIG. 5B. In these Figures, members and shapes used in common with thefastening assembly shown in FIG. 1 are denoted by the same referencenumerals.

As shown in FIG. 5, the inclined fastening metal-fitting 22 has aspring-steel molded product in which two engaging pieces 11 are disposedsymmetrically in the vertical direction of the Figures and a connectingportion 14 is integrally coupled between the engaging pieces 11. At acentral position of the connecting portion 14 in the vertical directionof the Figures, a coupling portion 23 on a thrust-directional sidethereof is left and a pull-directional side thereof is divided by alinking division groove 24. Since one of the engaging pieces 11 isintegrally connected to a base end of the connecting portion 14, asectional shape orthogonal to the insertion direction becomes a “T”shape (see FIG. 5B). The connecting portion 14 is formed to have thelinking width “Wc” almost equal to the opening width “Wo” for beingcapable of piecing the communication groove 6, and the linking height“Hc” of the connecting portion 14 (i.e., length between the two engagingpieces 11) is formed with a dimension approximately twice larger thanthe opening depth “Do” of the communication groove 6.

The side faces formed in the longitudinal direction at the positions onboth sides of the connecting portion 14, among the outer surfaces of theengaging pieces 11, constitute fastening surfaces 15. The engagementwidth “Wf” of the engaging piece 11 is formed to be larger than theopening width “Wo” so that the fastening surfaces 15 can be contactedand engaged with the engagement surfaces 9 of the engagement grooves 7.The engagement width “Wf” of the engaging piece 11 is formed to bealmost equal to or smaller than the inner width “Wi” to be inserted intothe engagement groove 7. The engagement height “Hf” is formed by such adimension as to be almost equal to or smaller than the inner depth “Di”to be inserted into the engagement groove 7. The entirety of theinclined fastening metal-fitting 22 having the above-described structurecan be inserted into the interiors of one set of communication groove 6and engagement groove 7, which are opposed to and communicate with eachother as shown in FIG. 5, by being thrust in the insertion direction.

In this inserted state, the respective fastening surfaces 15 of theengaging pieces 11 contact with the engagement surfaces 9 of theengagement grooves 7, so that the respective fastening surfaces 15cannot be removed from the connection surfaces 3 c of the blocks 1 a and1 b in the direction orthogonal thereto. Therefore, the two blocks 1 aand 1 b cannot be separated from each other via the inclined fasteningmetal-fitting 22 therebetween, i.e., the two blocks 1 a and 1 b can befastened via the inclined fastening metal-fitting 22.

As shown in the Figures, the end faces (tip faces) on a pull-directionalside of the engaging pieces 11 form inclined surfaces 25 opposed to eachother and forming an acute angle with respect to each of connectionsurfaces 3 c of the blocks 1 a and 1 b, and the end faces on thethrust-directional side of the entire inclined fastening metal-fitting22 are formed on the same plane. A screw hole 26 is formed in eachengaging piece 11 in a direction substantially orthogonal to theinclined surface 25, and the screw hole 26 pierces up to an outersurface 27 parallel to the fastening surface 15. A setscrew 29 (screwmember) whose tip 28 is taped as a fastening member is attached to eachscrew hole 26.

As shown in FIGS. 5B and 5C, when the setscrews 29 are screwed forwardin a state in which the engaging pieces 11 are inserted in theengagement grooves 7, the tips 28 of the setscrews protrude from theouter surfaces 27 of the engaging pieces, thereby abutting on the bottomfaces 10 of the engagement grooves. Accordingly, the inclined fasteningmetal-fitting 22 can be prevented from being pulled out from theengagement groove 7, thereby being certainly installed.

Then, when the setscrews 29 are further screwed forward, the fasteningsurfaces 15 of the engaging pieces 11 are strongly pressed in adirection of approaching each other due to a reaction force to anabutment force between the tips 28 of the setscrews and the bottom faces10 of the engagement grooves. The two communication grooves 6 under theopposite states are strongly clamped via the engagement surfaces 9.Therefore, the inclined fastening metal-fitting 22 serving as a fastenerapplies a fastening force to the two blocks 1 a and 1 b, therebybecoming capable of further firmly fastening them.

In addition, when the engaging pieces 11 are pressed against thecommunication grooves 6 due to a reaction force to a force abutting onthe bottom faces 10 of the engagement grooves obtained by making thetips 28 of the setscrews protrude, the coupling portion 23 serves as abending location and the entirety of the inclined fasteningmetal-fitting 22 can be readily elastically deformed in a direction inwhich the fastening surfaces 15 approach each other. Therefore, theengaging pieces 11 can be readily pressed against the communicationgrooves 6. Alternatively, if the fastening of the two blocks 1 a and 1 bis eliminated so as to separate them, the setscrews 29 are turnedbackward to eliminate the pressing forces of the engaging pieces 11.Thereafter, the blocks 1 a and 1 b are slid with respect to each otherin the longitudinal direction of the communication groove 6 and theengagement groove 7, thereby being readily separated. In a fastenerprovided with the above-mentioned fastening member, since frictionagainst wall faces of the engagement grooves 7 can be adjusted afterinsertion, a dimensional tolerance causing some degree of loose fit ispermissible.

FIG. 6A is a perspective view of an entirety of the inclined fasteningmetal-fitting 22 and of a positioning plate 30 used for it in thepresent embodiment, FIG. 6B is a front view of a state of incorporatingthe positioning plate 30 into one set of communication groove 6 andengagement groove 7 which are opposed to each other and of inserting theinclined fastening metal-fitting 22 therein, and FIG. 6C is aninsertion-directional cross-sectional view taken along line 6C-6C ofFIG. 6B. In these Figures, members and shapes used in common with thefastening assembly shown in FIG. 5 are denoted by the same referencenumerals.

As shown in FIG. 6, the positioning plate 30 is made of a plate materialbent into a substantially U shape so as to surround the end face on thethrust-directional side and two outer surfaces 27 of the inclinedfastening metal-fitting 22, and has such a shape that locking claws 31contacting with the end faces of the two members to be fastened areprovided at both ends thereof. First, the positioning plate 30 isattached to the inclined fastening metal-fitting 22 in a state in whichthe two blocks 1 a and 1 b contact with each other while the end faces 2thereof are aligned. Then, by being inserted into the interiors of oneset of communication groove 6 and engagement groove 7 opposed to eachother, excessive insertion therein in the thrust direction can beprevented and also pull-out of the inclined fastening metal-fitting 22can be readily carried out. The positioning plate 30 may be firstinserted into the interiors of the set of communication groove 6 andengagement groove 7 which are opposed to each other, and then theinclined fastening metal-fitting 22 may be installed at the insidesthereof.

FIG. 7A is a perspective view of the entirety of an enlarging dividedmetal-fitting serving as a fastener used in a fastening assemblyaccording to a third embodiment, FIG. 7B is a front view of theenlarging divided metal-fitting installed in the interiors of the set ofcommunication groove 6 and engagement groove 7 which are opposed to eachother, and FIG. 7C is an insertion-directional cross-sectional viewtaken along line 7C-7C of FIG. 7B. In these Figures, members and shapesused in common with the fastening assembly shown in FIG. 5 are denotedby the same reference numerals.

As shown in FIG. 7, the enlarging divided metal-fitting 32 integrallyhas the two engaging pieces 11 which are disposed symmetrically in thevertical direction of the Figures, and the connecting portion 14 betweenthe engaging pieces 11 is integrally formed therewith. At the centralposition in the vertical direction of the Figures, the coupling position23 thereof is left on the thrust-directional side, and is divided mostly(about two thirds) on the pull-directional side by the linking dividinggroove 24.

A protruding portion 33 is formed on the outer surface 27 of each of theengaging pieces 11 in the longitudinal direction, and a periphery ofeach engaging piece 11 is such that its sectional shape orthogonal tothe insertion direction is substantially cross-like (see FIG. 7B). Whenthis enlarging divided metal-fitting 32 is used, accommodating grooves34 into which the protruding portions 33 can be inserted are formed inthe bottom faces of the engagement grooves on sides of the fastenedblocks 1 a and 1 b. As shown in FIG. 7, the enlarging dividedmetal-fitting 32 having the above-described structure is thrust in theinsertion direction into the interiors of the set of communicationgroove 6 and engagement groove 7 which are opposed to and communicatewith each other, so that the entirety thereof can be inserted thereto.

As shown in the Figures, half of each engaging piece 11 on thepull-directional side is separated into an outer elastic deformationportion 36 and an inner elastic deformation portion 37 respectively inthe vertical direction of the Figures, by an engaging-piece dividinggroove 35 serving as a cut-in portion. Further, a screw hole 38 isformed at a center of the engaging-piece dividing groove 35. A taperedround surface having no screw thread is formed in each screw hole 38 onthe pull-directional side. A flat head screw 39, whose bearing surfacehas a comparatively large taper, is attached as a fastening member toeach screw hole 38.

As shown in FIG. 7, when the flat head screws 39 are screwed forward ina state in which the engaging pieces 11 are inserted in the engagementgrooves 7, the tapered bearing surface of the flat head screw 39penetrates as a wedge-shaped member the engaging-piece dividing groove35, whereby the engaging-piece dividing groove 35 is spread out. As aresult, the fastening surfaces 15 of the two inner elastic deformationportions 37 are strongly pushed in a direction of approaching eachother, and the two opposing communication grooves 6 are strongly clampedvia the engagement surfaces 9. Accordingly, the enlarging dividedmetal-fitting 32 serving as a fastener applies a fastening force to thetwo blocks 1 a and 1 b, thereby firm fastening them.

In the manner described above, also in the two blocks 1 a and 1 b in thestate of being fastened by the fastening assembly according to thepresent embodiment, firm fastening without anything protruding from thesurfaces of the blocks 1 a and 1 b can be carried out.

FIG. 8A is a perspective view of an entirety of a modification exampleof the enlarging divided metal-fitting shown in FIG. 7, FIG. 8B is afront view of the modification example of the enlarging dividedmetal-fitting installed in the interiors of one set of communicationgroove 6 and engagement groove 7 which are opposed to each othersimilarly to the above-described first embodiment, and FIG. 8C is aninsertion-directional cross-sectional view taken along line 8C-8C ofFIG. 8B. In these Figures, members and shapes used in common with thefastening assembly shown in FIG. 7 are denoted by the same referencenumerals.

In a modification example 40 of the enlarging divided metal-fittingshown in FIG. 8, screw threads are formed in a tapered manner over theentirety of the screw hole 41 formed on the engaging-piece dividinggroove 35 in the length direction, and a tapered screw is formed in thelength direction over the entirety of a screw member 42 (fasteningmember) to be screw-connected to the screw hole 41. A structure otherthan this is the same as that of the enlarging divided metal-fitting 32shown in FIG. 7.

Therefore, as shown in the Figures, when the screw members 42 arescrewed in a state of inserting the engaging pieces 11 in the engagementgrooves 7, the entirety of the tapered screw 42 penetrates, as awedge-shaped member, the engaging-piece dividing groove 35, therebyexpanding the engaging-piece dividing groove 35. As a result, thefastening surfaces 15 of the two inner elastic deformation portions 37are strongly pushed in the direction of approaching each other, and thetwo opposing communication grooves 6 are strongly clamped via theengagement surfaces 9. The modification example of the enlarging dividedmetal-fitting 32 applies a fastening force to the two blocks 1 a and 1b, thereby firmly fastening them.

FIG. 9A is a perspective view of an entirety of a wedge dividingmetal-fitting serving as a fastener used in a fastening assemblyaccording to a fourth embodiment, FIG. 9B is a front view of the wedgedividing metal-fitting installed in the fastened state in the interiorsof one set of communication groove 6 and engagement groove 7 which areopposed to each other, FIG. 9C is a cross-sectional view taken alongline 9C-9C of FIG. 9D, and FIG. 9D is an insertion-directionalcross-sectional view taken along line 9D-9D of FIG. 9B. In theseFigures, members and shapes common used in with the fastening assemblyshown in FIG. 5 are denoted by the same reference numerals.

As shown in FIG. 9, the wedge dividing metal-fitting 46 is constitutedso that two of a wedge metal-fitting 47 on the pull-directional side anda clamp metal-fitting 48 on the thrust-directional side (fasteningpieces) are assembled in the insertion direction via a screw member.Each of the wedge metal-fitting 47 and the clamp metal-fitting 48 has aheight almost equal to a distance (2Do+2Di) from the bottom face 10 ofone engagement groove of one set of communication groove 6 andengagement groove 7 communicating with each other to the bottom face 10of the other engagement groove, so that the wedge metal-fitting 47 isformed to have a width almost equal to the inner width “Wi” and theclamp metal-fitting 48 is formed to have a width almost equal to theopening width “Wo”.

The wedge metal-fitting 47 integrally includes, at both ends in thevertical direction of the Figures, the engaging pieces 11 which can beinserted into the engagement grooves 7. Between the two upper and lowerengaging pieces 11, the coupling portion 23 on the pull-directional sideis left and most thereof on the thrust-directional side is divided bythe linking dividing groove 24 in the vertical direction of the Figure.Each of end faces on the thrust-directional side of parts divided upperand lower forms an inclined face 49 (abutting face) forming an obtuseangle with respect to the outer surface 27 of each engaging piece 11.

The clamp metal-fitting 48 is such that the coupling portion 23 on thethrust-directional side is left and most thereof on the pull-directionalside is divided by the linking dividing groove 24 in the verticaldirection of the Figures. End faces of vertically divided parts on thepull-directional side form inclined surfaces 50 (abutting faces), whichare formed with such angles that they become parallel to the mutuallyopposing inclined surfaces 49 serving as end faces of the wedgemetal-fitting 47.

A hole penetrated in the insertion direction is formed in each of boththe coupling portions 23 of the wedge metal-fitting 47 and the clampmetal-fitting 48, wherein the hole of the wedge metal-fitting 47 ismerely a through hole 51 on which no screw thread is formed and the holeof the clamp metal-fitting 48 is a screw hole 52 on which a screw threadis formed. A bolt screw 53 is inserted from the end face of the wedgemetal-fitting 47 on the pull-directional side, a bolt-screw head 54 isengaged with the end face on the pull-directional side, and a screw partof the bolt screw 53 is screw-connected to the screw hole 52 of theclamp metal-fitting, so that the wedge metal-fitting 47 and the clampmetal-fitting 48 are assembled.

As shown in FIG. 9, the wedge dividing metal-fitting 46 having theabove-mentioned structure is thrust into the interiors of the set ofcommunication groove 6 and engagement groove 7 which are opposed to andcommunicate with each other, whereby the entirety thereof can beinserted. In a state in which the entirety is inserted, when the boltscrew 53 is turned so that the wedge metal-fitting 47 and the clampmetal-fitting 48 are strongly pressed against each other, pressingcomponent forces in a direction of approaching each other act on theengaging pieces 11 of the wedge metal-fitting 47 due to contact slidingcaused between the inclined surfaces 49 and 50 as shown in FIG. 9D. Inaddition, the outer surfaces 27 of the clamp metal-fitting 48 abut onthe bottom faces 10 of the engagement grooves, thereby being notdeformed any more. In other words, the clamp metal-fitting 48 and thebolt screw 53 serve as a fastening member in the wedge dividingmetal-fitting 46. Accordingly, the fastening surfaces 15 of the engagingpieces 11 of the wedge metal-fitting 47 are strongly pressed in thedirection of approaching each other, whereby the two mutually opposedcommunication grooves 6 are strongly clamped via the engagement surfaces9.

In the manner described above, also in the two blocks 1 a and 1 b underthe state of being fastened by the fastening assembly according to thepresent embodiment, the firm fastening without anything protruding fromthe surfaces of the blocks 1 a and 1 b can be carried out. Furthermore,the positioning plate 30 shown in FIG. 6 can be applied to the wedgedividing metal-fitting 46 of the present embodiment.

FIG. 10A is a perspective view of an entirety of an inclined dividingmetal-fitting serving as a fastener used in a fastening assemblyaccording to a fifth embodiment, FIG. 10B is a front view of theinclined dividing metal-fitting installed in the fastened state in theinteriors of one set of communication groove 6 and engagement groove 7which are opposed to each other, FIG. 10C is a cross-sectional viewtaken along line 10C-10C in FIG. 10D, and FIG. 10D is aninsertion-directional cross-sectional view taken along line 10D-10D ofFIG. 10B. In these Figures, members and shapes used in common with thefastening assembly shown in FIG. 9 are denoted by the same referencenumerals.

As shown in FIG. 10, the inclined dividing metal-fitting 57 isconstituted so that two trapezoidal metal-fittings 58 a and 58 b thereofon the pull-directional side and the thrust-directional side areassembled in the insertion direction via a screw member. The trapezoidalmetal-fittings 58 a and 58 b have connecting portions 62 a and 62 b(first connecting portion and second connecting portion), each of whichis formed with a height almost equal to a distance (2Do+2Di) from thebottom face 10 of one of the engagement grooves in the set ofcommunication groove 6 and engagement groove 7 communicating with eachother to the bottom face 10 of the other engagement groove and with awidth almost equal to the opening width “Wo” of the communication groove6. These connecting portions 62 a and 62 b are arranged so as to beopposed to each other by mutually parallel inclined surfaces 59 a and 59b (abutting faces).

The connecting portion 62 b of the trapezoidal metal-fitting 58 a on thepull-directional side integrally includes the engaging piece 11 capableof being inserted into the engagement groove 7 at the upper-side end ofthe Figures, and the connecting portion 62 b of the trapezoidalmetal-fitting 58 b on the thrust-directional side integrally includesthe engaging piece 11 capable of being inserted into the engagementgroove 7 at the lower-side end of the Figures. Accordingly, the twoengaging pieces 11 are arranged so that the respective fasteningsurfaces 15 are mutually shifted in the longitudinal direction andopposed to each other. Each of the inclined surfaces 59 a and 59 b ofthe two trapezoidal metal-fittings 58 a and 58 b opposed to each otherforms an obtuse angle with respect to the outer surface 27 on a side onwhich the engaging piece 11 is provided.

In a state in which the two trapezoidal metal-fittings 58 a and 58 b areserially arranged so that the inclined surfaces 59 a and 59 b areopposed to each other, a hole penetrating the entirety of the inclineddividing metal-fitting 57 in the insertion direction is formed at aheight level including the engaging piece 11 of the trapezoidalmetal-fitting 58 a on the pull-directional side. The hole of thetrapezoidal metal-fitting 58 a on the pull-directional side is merely athrough hole 60 on which no screw thread is formed, and the hole of thetrapezoidal metal-fitting 58 b on the thrust-directional side is a screwhole 61 on which a screw thread is formed. The bolt screw 53 (screwmember) is inserted from the pull-directional-side end face of thetrapezoidal metal-fitting 58 a on the pull-directional side and thebolt-screw head 54 is engaged with the end face on the pull-directionalside and the screw part of the bolt screw 53 is screwed in a screw hole61 of the trapezoidal metal-fitting 58 b on the thrust-directional side,so that the two trapezoidal metal-fittings 58 a and 58 b are assembled.

As shown in FIG. 10, the inclined dividing metal-fitting 57 having theabove-mentioned structure is thrust into the interiors of the set ofcommunication groove 6 and engagement groove 7 which are opposed to andcommunicate with each other, the entirety thereof can be inserted. Inthe state in which the entirety is inserted, when the bolt screw 53 isturned to increase the pressing force acting mutually between the twotrapezoidal metal-fittings 58 a and 58 b, as shown in FIG. 10D, thepressing component force in the mutually opposing directions, i.e., inthe upward direction and the downward direction of the Figures acts onthe trapezoidal metal-fittings 58 a and 58 b due to the contact slidingbetween the inclined surfaces 59 a and 59 b. Since the inclined surfaces59 a and 59 b are formed with the above-described angle, the pressingcomponent force directed downward in the Figures acts on the trapezoidalmetal-fitting 58 a on the pull-directional side and the pressing forcedirected upward in the Figures acts on the trapezoidal metal-fitting 58b on the thrust-directional side. Accordingly, the fastening surfaces 15of the engaging pieces 11 of the respective trapezoidal metal-fittings58 a and 58 b are strongly pressed in the direction of approaching eachother, whereby the two opposing communication grooves 6 are stronglyclamped via the engagement surfaces 9.

In the manner described above, also in the two blocks 1 a and 1 b underthe state of being fastened by the fastening assembly according to thepresent embodiment, the firm fastening without anything protruding fromthe surfaces of the blocks 1 a and 1 b can be carried out. Furthermore,the positioning plate 30 shown in FIG. 6 can be applied to the inclineddividing metal-fitting 57 of the present embodiment.

FIG. 11A is a perspective view of an entirety of an H-shapedmetal-fitting serving as a fastener used in a fastening assemblyaccording to a sixth embodiment, and FIG. 11B is a front cross-sectionalview of the H-shaped metal-fitting installed in a state of beingfastened in the interiors of one set of communication groove 6 andengagement groove 7 which are opposed to each other. If each length ofthe members to be fastened, the communication groove 6, and theengagement groove 7 is larger than that of an ordinary case incomparison with the width of each groove, the H-shaped metal-fitting 63of the present embodiment is an intermediate fastener for fastening anintermediate position thereof. In these Figures, members and shapes usedin common with the fastening assembly shown in FIG. 2 are denoted by thesame reference numerals.

As shown in FIG. 11, the H-shaped metal-fitting 63 is formed integrallyso that the two engaging pieces 11 capable of being inserted into theengagement grooves 7 are disposed symmetrically in the verticaldirection of the Figures by sandwiching the connecting portion 14therebetween. The H-shaped metal-fitting 63 with such a structure can beentirely inserted into the interiors of one set of communication groove6 and engagement groove 7 which are opposed to and communicate with eachother. Also, as shown in the Figures, a screw hole 64 penetrating theH-shaped metal-fitting 63 in a direction orthogonal to the outersurfaces 27 of the engaging pieces 11 is formed, and a setscrew 65 isattached to the inside thereof. Note that when this intermediatefastener is used, an accommodating groove 67 on which a tip 66 of thesetscrew abuts is desirably formed on the bottom face 10 of theengagement groove as shown in the Figures.

In the procedure for attaching it, first, the engaging piece 11 on aside, on which the tip 66 of the setscrew is disposed in the engagementgroove 7 of the lower-side block 1 b of FIG. 11, is inserted from anopening of an end of the engagement groove 7, thereby being disposed ata predetermined middle position of the engagement groove 7 in itslongitudinal direction. Then, the setscrew 65 is screwed thereto so asto abut the tip 66 of the setscrew and the bottom face of theaccommodating groove 67, whereby the fastening surfaces 115 of theengaging pieces 11 is pressed against the engagement surfaces 9 of theengagement grooves 7 by a reaction force thereof and the H-shapedmetal-fitting 63 is fixed to the communication groove 6 and engagementgroove 7 of one block 1 b. At this time, half of the connecting portion14 and one of the engaging pieces 11 become in a state of protrudingfrom the connection surface 3 c. By making the other block (upper-sideblock 1 a of FIG. 11B) to be fastened contact by both connectionsurfaces 3 c and by inserting the H-shaped metal-fitting 63 into thecommunication groove 6 and the engagement groove 7 to be slid in thelongitudinal direction, the fastening at the intermediate position canbe achieved.

According to the fastening assembly of the present embodiment that hasbeen thus assembled, even when the two blocks 1 a and 1 b to be fastenedare long in the longitudinal direction, occurrence of displacement and agap at the intermediate position thereof can be prevented, whereby thereliable fastening can be achieved.

Further, the intermediate fastener used in the fastening assembly of thepresent embodiment may be constituted by the following modificationexample. FIG. 12A is a perspective view of an entirety of a flatinclination H-shaped metal-fitting which is a first modification exampleof the intermediate fastener; FIG. 12B is a front cross-sectional viewtaken along line 12B-12B of FIG. 12C showing the flat inclinationH-shaped metal-fitting installed in the interiors of one set ofcommunication groove 6 and engagement groove 7 which are opposed to eachother; and FIG. 12C is a plane cross-sectional view taken along line12C-12C of FIG. 12B. In these Figures, members and shapes used in commonwith the fastening assembly shown in FIG. 11 are denoted by the samereference numerals.

As shown in FIG. 12, a flat inclination H-shaped metal-fitting 71 hasthe two engaging pieces 11, each of which is formed into a prismaticshape having a parallelogram section in which front and rear end faces72 a and 72 b viewed from the outer surface 27 thereof are inclined byan angle “X” with respect to the insertion direction, wherein the widthin a direction orthogonal to the insertion direction is equal to theinner width “Wi” of the engagement groove 7 and a distance between thetwo parallel end faces 72 a and 72 b is formed to be equal to theopening width “Wo” of the communication groove 6. The connecting portion14 is formed into a cylindrical shape with a diameter equal to theopening width “Wo” of the communication groove 6.

By virtue of such a structure, when the flat inclination H-shapedmetal-fitting 71 is attached to the first block 1 b, as shown by thechain double-dashed lines in FIG. 12C, one of the engaging pieces 11 canbe passed through from the communication groove 6 by taking a posture ofbeing rotated by an angle “X” about a central axis of the connectingportion 14. Thereafter, by returning the angle “X”, as shown by thesolid lines in FIG. 12C, a state of inserting one engaging piece 11 intothe engagement groove 7 can be achieved while a good posture ismaintained. After fixing the position and posture by the setscrew 65,the other block 1 a is slid in the longitudinal direction, thereby beingable to be fastened at the intermediate position.

As described above, according to the intermediate fastener of thismodification example, even when the communication grooves 6 and theengagement grooves 7 are long in the longitudinal direction, thefastener can be readily installed from the longitudinal-directionalintermediate positions without being inserted from the openings of theends of the communication groove 6 and the engagement groove 7. Under astate of the good posture, the posture can be certainly fixed since bothwidth-directional ends of each engaging piece 11 surface-contact withboth width-directional side faces of the engagement groove 7. Note thatone of the engaging pieces 11 may be formed into a prismatic shapehaving a parallelogram section capable of passing through thecommunication groove 6 and the other of the engaging pieces 11 may beformed into a cuboid as shown in FIG. 11.

FIG. 13A is a perspective view of an entirety of a flat round H-shapedmetal-fitting which is a second modification example of the intermediatefastener; FIG. 13B is a front cross-sectional view taken along line13B-13B of FIG. 13C showing the flat round H-shaped metal-fittinginstalled in the interiors of one set of communication groove 6 andengagement groove 7 which are opposed to each other; and FIG. 13C is aplane cross-sectional view taken along line 13C-13C of FIG. 13B. Inthese Figures, members and shapes used in common with the fasteningassembly shown in FIG. 11 are denoted by the same reference numerals.

As shown in FIG. 13, a flat round H-shaped metal-fitting 73, in whichthe entire thickness with respect to the insertion direction is equal tothe opening width “Wo” of the communication groove 6 and bothwidth-directional ends of each engaging piece 11 each have a cylindricalside face 74 with a diameter equal to the inner width “Wi” of theengagement groove 7.

By virtue of such a structure, when the flat round H-shapedmetal-fitting 73 is attached to the first block 1 b, as shown by thechain double-dashed lines in FIG. 13C, one of the engaging pieces 11 canbe passed through and inserted into the communication groove 6 by takinga posture of rotating by an angle of 90 degrees about the central axisof the connecting portion 14. Thereafter, by returning 90 degrees, asshown by the solid lines in FIG. 13C, one of the engaging pieces 11 canbe inserted into the engagement groove 7 under a state of maintaining agood posture. After fixing the position and posture by the setscrew 65,the other block 1 a can be slid in the longitudinal direction, therebybeing able to be fastened at the intermediate position.

As described above, according to the intermediate fastener of thismodification example, similarly to the intermediate fastener of thefirst modification example, the fastener can be readily installed fromthe intermediate positions of the communication groove 6 and theengagement groove 7 in the longitudinal direction. Note that only one ofthe engaging pieces may be formed to have such thickness as to becapable of passing through the communication groove 6.

Fastening by use of the fastening assemblies of the above-describedembodiments is not limited to the case where mere blocks are fastened asshown in FIG. 1, and is also suitable for, for example, mutuallyfastening manifolds 20 in a stacking valve 19 as shown in FIG. 14. Inthis case, externally fixed rails etc. for fixing the manifolds 20 arenot particularly required, and many manifolds 20 can be added and fixedwithout being limited by the length of such externally fixed rails. Thiscase is advantageous in that the manifolds 20 and solenoid valves 21fixed thereon can be easily attached, detached, or replaced by thrustinginto or pulling out the fasteners (insertion fasteners 8).

In addition, fastening by use of the fastening assemblies of theabove-described embodiments is also suitable for, for example, as shownin FIG. 15, the case where a plurality of fluid pressure cylinders 16are mutually fastened by cylinder tubes 17 so as to constitute a fluidpressure cylinder unit. In this case, by fastening piston rods 18 so asto be disposed on the same side, as shown in the Figure, and byactuating and controlling the same object using both of the piston rods18, a driving force can be increased. Or, by fastening the piston rods18 so as to be mutually disposed on the opposite side, as describedblow, the total length of a stroke can be doubled. Also, in addition tomutually fastening of the two cylinder tubes 17 as shown in the figure,even the case of constituting another fluid pressure cylinder unit byfastening one cylinder tube 17 to a casing and bracket, etc., or byfastening it to an attachment etc. may be applied. Even in this case,there is an advantage in that the fluid pressure cylinders 16 can bereadily attached, detached, and replaced.

Hereinafter, embodiments of a fluid pressure cylinder unit fastened andconstituted by the above-described fastening assembly will be described.FIG. 16 is a perspective view of an entirety of a fluid pressurecylinder unit according to a first embodiment of the present invention,wherein FIG. 16A is a perspective view showing a before-assembly stateand FIG. 16B is a perspective view showing an assembled state. Each oftwo fluid pressure cylinders 101 a and 101 b is a pneumatic cylinderemploying compressed air as working fluid (fluid pressure), wherein apiston rod 104 protrudes from one end face 103 of each of the cylindertubes 102 serving as two members to be fastened. The piston rod 104 isprovided so that an object to be driven can be driven reciprocably in astraight-line direction when the compressed air is fed or dischargedthrough an unshown feed/discharge port. Hereinafter, the fluid pressurecylinders used in the embodiments are assumed to be pneumatic cylinders.

As shown in FIG. 16, in the two pneumatic cylinders 101 a and 101 b, thepiston rods 104 thereof are disposed in the same direction and inparallel to each other, the cylinder tubes 102 are made to contact witheach other by connection surfaces 105 c thereof to be fastened via theinsertion fastener 8 serving as a fastener, and a common tip plate 107 aserving as a linking member is attached to the tips of the piston rods104, whereby a twin rod cylinder is constituted. In this structure, thetwo cylinder tubes 102 to be fastened serve mutually as attachments.

Each of the cylinder tubes 102 is such that its end face 103 issubstantially square and its entirety is a long cuboid shape in an axialdirection of the piston rod 104. The communication groove 6 opened andextending in a longitudinal direction along an axial direction and theengagement groove 7 communicating therewith are formed in each of fourside faces 105 thereof, and the communication grooves 6 and theengagement grooves 7 of the connection surfaces 105 c contacting witheach other are coupled via the insertion fasteners 8 serving asfasteners. In this linking state, the entirety of the insertion fastener8 is inserted into and installed in the interiors of the set ofcommunication groove 6 and engagement groove 7 which are in opposed andcommunicated states. In each of the cylinder tubes 102 shown in FIG. 16,although the communication groove 6 and the engagement groove 7 areformed in each of the four side faces 105, the communication groove 6and the engagement groove 7 may be formed at least only in theconnection surfaces 105 c by which the cylinder tubes 102 contact witheach other. Note that although shapes of the end faces 103 of thecylinder tubes 102 are square, they may be rectangular.

The pneumatic cylinder unit of the present embodiment shown in FIG. 16has a structure in which the insertion fasteners 8 serving as fastenersare accommodated and disposed in the interiors of the two cylinder tubes102 and there is nothing protruding from the surfaces of the cylindertubes 102 in spite of a fastened state. Therefore, the pneumaticcylinder unit of the present embodiment has a fastening structuresuitable for saving the installation spaces depending on recentlydownsizing of the devices.

In addition, if the communication grooves 6 and the engagement grooves 7provided long in the two cylinder tubes 102 are in states of evenpartially being opposed to and communicating with each other, theinsertion fastener 8 can be inserted into and fastened on such acommunicating location. Therefore, even when the relative arrangementbetween the two cylinder tubes 102 is arbitrarily changed depending on adirection of forming the communication grooves 6, fastening can becarried out by inserting the insertion fastener 8. In addition, if aregion in which the communication grooves 6 are mutually communicated issufficiently long, the insertion fastener 8 can be inserted at arbitraryposition within the communicating region. Therefore, fastening locationscan be also set at arbitrary positions.

In addition, the pneumatic cylinder unit of the present embodiment has astructure in which since the two pneumatic cylinders 101 a and 101 bdisposed parallel are certainly fastened in the above-described mannerand the same tip plate 107 a is driven, the driving force is almostdoubled in comparison with the case of being driven by one pneumaticcylinder and rigidity is enhanced.

FIG. 17 is a perspective view of an entirety of a pneumatic cylinderunit according to a second embodiment of the present invention, whereinFIG. 17A is a perspective view showing a before-assembly state and FIG.17B is a perspective view showing an assembled state. In these Figures,members and shapes used in common with the pneumatic cylinder unit shownin FIG. 16 are denoted by the same reference numerals.

As shown in FIG. 17, in a state in which one guide rod 115 is disposedin parallel with and installed in the guide units 114 a and 114 b, therespective connection surfaces 105 c are fastened to each other throughthe insertion fastener 8 and a common tip plate 107 b serving as alinking member is attached to the tips of the piston rod 104 and theguide rod 115, whereby the guide-installed cylinder is constituted.Also, this structure serves as an attachment in which guide blocks 116of the two guide units 114 a and 114 b are fastened to the cylinder tube102.

The guide units 114 a and 114 b are such that, with respect to the guideblocks 116 serving as members to be fastened, the same guide rods 115between both ends thereof is made to pierce and protrude and beinstalled extendably and retractably and the guide rod 115 is supportedin the guide block 116 by a ball bearing (not shown) so as to be slidsmoothly. The guide block 116 has end faces, each of which has the sameshape as that of the cylinder tube 102, and is a cuboid shape axiallyshorter in length than the cylinder tube 102, wherein the communicationgroove 6 and the engagement groove 7 are formed in each of the four sidefaces thereof. By inserting the entirety of the insertion fastener 8into the interiors of one set of communication groove 6 and engagementgroove 7 which are opposed to and communicate with each other at theconnection surface 105 c of the cylinder tube 102, each guide block 116becomes in a state of being fastened to the cylinder tube 102.

The above-described pneumatic cylinder unit of the present embodimenthas a fastening structure suitable for saving the installation spacessimilarly to the above-described first embodiment and is constituted sothat since two guide units 114 a and 114 b guide the pneumatic cylinder101 a, a stable operation can be obtained even if the tip plate 107 b islong. The guide block 116 may be formed with the same length as that ofthe cylinder tube 102, and the ball bearing provided in the guide block116 may be a slide bearing.

FIG. 18 is a perspective view of an entirety of a pneumatic cylinderunit according to a third embodiment of the present invention, whereinFIG. 18A is a perspective view showing a before-assembly state and FIG.18B is a perspective view showing an assembled state. In these Figures,members and shapes used in common with the pneumatic cylinder unit shownin FIG. 16 are denoted by the same reference numerals.

As shown in FIG. 18, in the two pneumatic cylinders 101 a and 101 b, thepiston rods 104 are arranged parallel and in the same direction, and thecylinder tubes 102 are made to contact with each other by the connectionsurfaces 105 c and are fastened via the insertion fastener 8. Two setsof guide unit pairs 114 a and 114 b, and 114 c and 114 d, that is, therespective two guide units 114 a to 114 d being arranged in parallel toeach other and fastened, sandwich a cylinder pair 101 a and 101 btherebetween parallel and from an upper and lower directions of theFigures to be arranged in 2×3 and all of the contacting connectionsurfaces 105 c are mutually fastened by the insertion fasteners 8. Acommon tip plate 107 c serving as a linking member is attached to allthe tips of the piston rods 104 and the guide rods 115, whereby a liftercylinder is constituted. In this structure, the two fastened cylindertubes 102 serve mutually as attachments, and other four guide blocks 116serves as attachments that are fastened on the two cylinder tubes 102.

The above-described pneumatic cylinder unit has a fastening structuresuitable for saving the installation spaces similarly to theabove-described first embodiment, and is constituted so that since twosets of guide unit pairs 114 a and 114 b, and 114 c and 114 d guide oneset of pneumatic cylinder pair 101 a and 101 b, a doubled driving forceand a stable operation can be obtained with respect to the tip plate 107c having an area approximately 2×3 times larger than a section of thecylinder tube 102.

FIG. 19 is a perspective view of an entirety of a pneumatic cylinderunit according to a fourth embodiment of the present invention, whereinFIG. 19A is a perspective view showing a before-assembly state and FIG.19B is a perspective view showing a assembled state. In these Figures,members and shapes used in common with the pneumatic cylinder unit shownin FIG. 16 are denoted by the same reference numerals.

As shown in FIG. 19, in the two pneumatic cylinders 101 a and 101 b, therespective piston rods 104 are arranged in opposite direction and inparallel to each other, the cylinder tubes 102 are made to contact witheach other by the connection surfaces 105 c and fastened via theinsertion fasteners 8, and chuck plates 117 serving as chuck members areattached to the respective piston rods 104, whereby an air chuck isconstituted. In this structure, the two cylinder tubes 102 fastenedserve mutually as attachments.

Each chuck plate 117 has a gripper 118 formed to extend from aconnection position with the piston rod 104 in a lower direction of theFigures, and a support rod 119 is attached to each chuck plate 117. Ineach cylinder tube 102, a support rod hole 120 is formed in an end face103 located on a side opposite to an extension side of the piston rod104, and the support rod 119 is slidably inserted into the support rodhole 120 in being assembled. That is, each chuck plate 117 is stablysupported by two members of the piston rod 104 and the support rod 119,and drive for reciprocation with respect to the cylinder tubes 102 iscarried out by movement of the piston rods 104. When the two chuckplates 117 are reciprocated, an opening/closing operation between thechuck plates 117 is carried out.

The above-described pneumatic cylinder unit of the present embodimenthas a fastening structure suitable for saving the installation spacessimilarly to the above-described first embodiment, and is constituted sothat by performing the opening/closing operation between the chuckplates 117, some workpiece etc. therebetween can be gripped.

FIG. 20 is a perspective view of an entirety of a pneumatic cylinderunit according to a fifth embodiment of the present invention, whereinFIG. 20A is a perspective view showing a before-assembly state and FIG.20B is a perspective view showing an assembled state. In these Figures,members and shapes used in common with the pneumatic cylinder unit shownin FIG. 16 are denoted by the same reference numerals.

As shown in FIG. 20, in the two pneumatic cylinders 101 a and 101 b, therespective piston rods 104 are arranged parallel and in the samedirection, the cylinder tubes 102 are made to contact with each other bythe connection surfaces 105 c to be fastened via the insertion fasteners8 serving as fasteners, and a common tip plate 107 d serving as alinking member is attached to the tips of the piston rods 104. Guiderails 121 are disposed parallel on the two side faces 105 locatedparallel on the respective pneumatic cylinders 101 a and 101 b, twoguide plates 122 are slidably installed on each of the guide rails 121,and a common slide table 123 a attached to the guide plates 122 isconnected to the piston rods 104 via the tip plate 107 d, whereby atable-attached twin guide cylinder is constituted. In this structure,the two cylinder tubes 102 to be fastened serve mutually as attachments.

The guide rail 121 is formed into a cuboid having a rail width “Wr”larger than the opening width “Wo” and a rail height “Hr”, i.e., almostthe same height as that of the cylinder tube 102 so as not to pierce thecommunication groove 6, and therefore is disposed so as to overlap withthe communication groove 6 and combined and fixed with the nut and screwinserted into the engagement groove 7, thereby being fixed. The guideplate 122 is a plate material formed into a square whose one side hasalmost the same width as that of the cylinder tube 102. On a lowersurface thereof, a rail groove 124 with a groove width almost equal tothe rail width “Wr” and groove depth shallower than the rail height “Hr”is formed so as to fit the guide rail 121 therein and be slid. The slidetable 123 a is a rectangular plate material having almost the same widthas that of a total of two pneumatic cylinders 101 a and 101 b, and isscrewed on the four guide plates 122, whose two are serially arranged oneach guide rail 121, and is fixed to one side face of the tip plate 107d attached to the piston rods 104. That is, the slide table 123 a canapply a load to the side faces 105 of the cylinder tubes 102 via theguide plates 122 and the guide rails 121 and reciprocate axially by theoperations of the piston rods 104.

The above-described pneumatic cylinder unit of the present embodimenthas a fastening structure suitable for saving the installation spacessimilarly to the above-described first embodiment and has a structure inwhich a stably reciprocating operation can be carried out by a doubleddriving force while the loads are applied from the vertical and lateraldirections of the cylinder tubes 102.

In addition, the table-attached guide cylinder includes a structure of atable-attached single guide cylinder having only one pneumatic cylinder101 a and formed with half of the entire width, as shown in FIG. 21.

FIG. 22 is a perspective view of an entirety of a pneumatic cylinderunit according to a sixth embodiment of the present invention, whereinFIG. 22A is a perspective view showing a before-assembly state and FIG.22B is a perspective view showing an assembled state. In these Figures,members and shapes used in common with the pneumatic cylinder unit shownin FIG. 16 are denoted by the same reference numerals.

As shown in FIG. 22, in the two pneumatic cylinders 101 a and 101 b, therespective piston rods 104 are mutually arranged parallel and in anopposite direction, the cylinder tubes 102 are made to contact with eachother by the connection surfaces 105 c to be fastened via the insertionfasteners 8, and a tip plate 107 e is attached to the respective pistonrods 104. Two guide rails 121 and four guide plates 122 are installed oneach of upper and lower surfaces of the entire pneumatic cylinder pair101 a and 101 b, and the slide tables 123 a attached to the faces arelinked to the piston rods 104 via the tip plates 107 e located on theopposite side, whereby a double-stroke cylinder is constituted. In thisstructure, the two cylinder tubes 102 to be fastened serve mutually asattachments.

The above-described pneumatic cylinder unit of the present embodimenthas a fastening structure suitable for saving the installation spacessimilarly to the above-described first embodiment, and is constituted sothat the staple reciprocating operation can be carried out by thedoubled stroke while the loads are applied from the vertical and lateraldirections of the cylinder tubes 102.

FIG. 23 is a perspective view of an entirety of a pneumatic cylinderunit according to a seventh embodiment of the present invention, whereinFIG. 23A is a perspective view showing a before-assembly state and FIG.23B is a perspective view showing an assembled state. In these Figures,members and shapes used in common with the pneumatic cylinder unit shownin FIG. 16 are denoted by the same reference numerals.

As shown in FIG. 23, in the two pneumatic cylinders 101 a and 101 b, therespective piston rods 104 are directed to the same direction and areall arranged parallel so as to sandwich a spacer block 125 therebetween.The two pneumatic cylinders 101 a and 101 b and the spacer block 125 aremutually made to contact with each other by the connection surfaces 105c and fastened via the insertion fasteners 8 serving as fasteners, and acommon tip plate 107 f serving as a linking member is attached to thetips of the two piston rods 104, whereby a spacer-attached twin-rodcylinder is constituted. In this structure, the spacer block 125 and thetwo cylinder tubes 102 to be fastened serve mutually as attachments.

The spacer block 125 has a cuboid shape with the same dimensions asthose of the cylinder tube 102, wherein the communication groove 6 andthe engagement groove 7 are formed in each of four side faces 105thereof. In the spacer block 125 shown in FIG. 23, although thecommunication groove 6 and the engagement groove 7 are formed in each ofthe four side faces 105, the communication groove 6 and the engagementgroove 7 may be formed only in at least the respective connectionsurfaces 105 c connected to the cylinder tubes 102. In addition, asshown in FIG. 24, the spacer block may be a spacer block 126 havingpreliminarily a shape of a half portion of a fastener on the connectionsurfaces 105 c with the cylinder tubes, i.e., having a shape of halvesof the connecting portion 14 and the engaging pieces 11. In this case,the fastener does not require being prepared as independent parts.

The above-described pneumatic cylinder unit of the present embodimenthas a fastening structure suitable for saving the installation spacessimilarly to the above-described first embodiment, and is constituted sothat the driving force is doubled and further the rigidity is enhanced.

FIG. 25 is a perspective view of an entirety of a pneumatic cylinderunit according to an eighth embodiment of the present invention, whereinFIG. 25A is a perspective view showing a before-assembly state and FIG.25B is a perspective view showing an assembled state. In these Figures,members and shapes used in common with the pneumatic cylinder unitsshown in FIG. 16 and FIG. 23 are denoted by the same reference numerals.

As shown in FIG. 25, the guide units 114 a and 114 b are disposed onboth sides of one pneumatic cylinder 101 a regarded as a center, and thepneumatic cylinder 111 a and the guide units 114 a and 114 b sandwichthe spacer block 125 therebetween and all are disposed parallel. Theyare made to contact with each other by the connection surfaces 105 c andfastened via the insertion fasteners 8 serving as fasteners, and acommon tip plate 107 g serving as a linking member is attached to theall tips of the piston rods 104 and the guide rods 115, whereby aspacer-and-guide-attached cylinder is constituted. In this structure,the two spacer blocks 125 and the two guide blocks 116 serve as anattachment fastened to the cylinder tube 102.

The above-described pneumatic cylinder unit of the present embodimenthas a fastening structure suitable for saving the installation spacessimilarly to the above-described first embodiment, and is constituted sothat an stable operation can be carried out with high rigidity even ifthe tip plate 107 g is formed into an elongated shape equal to a totalof sectional dimensions of the five cylinder tubes 102.

FIG. 26 is a perspective view of an entirety of a pneumatic cylinderunit according to a ninth embodiment of the present invention, whereinFIG. 26A is a perspective view showing a before-assembly state and FIG.26B is a perspective view showing an assembled state. In these Figures,members and shapes used in common with the pneumatic cylinder unitsshown in FIGS. 16, 20, and 23 are denoted by the same referencenumerals.

As shown in FIG. 26, in the two pneumatic cylinders 101 a and 101 b, thepiston rods 104 are respectively directed to the same direction andsandwich the spacer block 125 therebetween, whereby all are arrangedparallel. They are made to contact with each other by the connectionsurfaces 105 c and fastened via the insertion fasteners 8 serving asfasteners, and a common tip plate 107 h serving as a linking member isattached to the tips of the two piston rods 104. In addition, the guiderail 121 is installed parallel on each of the two side faces 105 locatedin parallel to the respective pneumatic cylinders 101 a and 101 b, twoguide plates 122 are slidably installed on each of the guide rails 121,and a common slide table 123 b attached to the guide plates 122 isconnected to the piston rods 104 via the tip plate 107 h, whereby atable-and-spacer-attached twin guide cylinder is constituted. In thisstructure, the spacer block 125 and the two cylinder tubes 102 to befastened serve mutually as attachments.

The above-described pneumatic cylinder unit of the present embodimenthas a fastening structure suitable for saving the installation spacessimilarly to the above-described first embodiment, and is constituted sothat the driving force is doubled and further the rigidity is enhancedwhile the loads are applied from the vertical and lateral directions ofthe cylinder tubes 102.

In addition, hereinafter, an embodiment of the case of applying arodless cylinder to the pneumatic cylinder to be fastened by theabove-described fastening assemblies will be described. FIG. 27 is aperspective view showing a pneumatic cylinder according to a tenthembodiment of the present invention; FIG. 28 is an exploded perspectiveview of FIG. 27; FIG. 29 is a partially-omitted vertical cross-sectionalview showing the rodless cylinder shown in FIGS. 27 and 28; and FIG. 30is a transverse cross-sectional view of FIG. 29. In these Figures,members and shapes used in common with the pneumatic cylinder unit shownin FIG. 16 are denoted by the same reference numerals.

This pneumatic cylinder unit 201 has a rodless cylinder 211 and a linearguide 212 serving as an attachment connected thereto, i.e., a guidemember. The rodless cylinder 211 is a slit type and, as shown in FIG.29, has a cylinder tube whose outer circumferential shape in transversesection is a quadrangle, i.e., a casing 213, and end covers 214 and 215are attached to both ends thereof. Two pistons 217 and 218 are attachedto a circular-transverse-sectional cylinder chamber 216 formed in thecasing 213 so as to reciprocate axially, and these pistons 217 and 218are connected by a piston yoke 219.

A pneumatic chamber 221 is formed between the end cover 214 and thepiston 217. When compressed air is fed from a feed/discharge port 214 acommunicating with the pneumatic chamber 221 and formed in the end cover214, the pistons 217 and 218 and the piston yoke 219 are drivenrightward in FIG. 29. A feed/discharge port 215 a is formed in the endcover 215 so as to communicate with a pneumatic chamber 222 formedbetween the end cover 215 and the piston 218. When compressed air is fedfrom the feed/discharge port 215 a, the pistons 217 and 218 and thepiston yoke 219 are driven leftward.

The piston yoke 219 includes, as shown in FIG. 30, a cylindrical portion219 a in which a notch portion is formed and to both ends of which thepistons 217 and 218 are fixed, and a connecting portion 219 b protrudingto the outside of the casing through a slit 224 formed in areciprocation guide surface 223 of the casing 213, wherein areciprocating body 225 sliding along the reciprocation guide surface 223of the casing 213 is attached to the connecting portion 219 b.

In order to prevent an air leakage from the pneumatic chambers 221 and222 through the slit 224 when the reciprocating body 225 is driven bythe compressed air fed to each of the pneumatic chambers 221 and 222, aninner sealing band 226 is fixed to both ends of the casing 213 and theinner sealing band 226 passes through an interior of the cylindricalportion 219 a of the piston yoke 219. Meanwhile, in order to preventdusts etc. from entering into the interior of the slit 224 from theoutside, an outer sealing band 227 is fixed to both ends of the casing213, and the outer sealing band 227 contacts with an outer surface ofthe piston yoke 219.

A T-slot 229 having the communication groove 6 and the engagement groove7 is formed in whole and in a longitudinal direction on each of twomutually-opposing side faces 228 of the casing 213, each of which formsa right angle with respect to the reciprocation guide surface 223,thereby linearly extending along each side face 228.

The linear guide 212 connected to such a slit-type rodless cylinder 211has a rod-like attachment member 231 whose outer shape in transversesection is quadrate, wherein a guide rail 233 is attached to anattachment surface 232 of the attachment member 231 by unshown screwmembers penetrating attachment holes formed therein. As shown in FIG.28, sliders 234 are slidably mounted on the guide rail 233, and thesliders 234 and the reciprocating body 225 are provided with areciprocating table 235 for connecting them. Therefore, when the pistons217 and 218 are driven by feeding the compressed air to the pneumaticchambers 221 and 222, the reciprocating table 235 moves in astraight-line direction and its movement is guided by the guide rail233.

T-shaped slots 239 are formed in whole and in the longitudinal directionon the attachment surface 232 and other three side faces 236 of theattachment member 231, thereby being linearly extending along theattachment surface 232 and the side faces 236, respectively. A rod-likespacer 237 is assembled into the T-shaped slot 239 formed in theattachment surface 232 and screw holes 237 a, through which the screwmembers for attaching the guide rail 233 to the attachment member 231pass, are formed in the spacer 237. However, the T-shaped slots 239 maybe formed only in other three side faces 236 without forming theT-shaped slot 39 in the attachment surface 32. In this case, femalescrew holes may be directly provided on the attachment surface 232.

The casing 213 of the rodless cylinder 211 and the attachment member 231of the linear guide 212 are connected, in a state in which the sidefaces 228 and 236 serving as connection surfaces are opposed to eachother, by the insertion fasteners 8 to be embedded in the T-shaped slots229 and 239 formed in the respective connection surfaces. Threeinsertion fasteners 8 are embedded in both ends and alongitudinal-directional intermediate position of the T-shaped slots 229and 239.

The T-shaped slot 229 is formed on each of the two mutually-parallelconnection surfaces, i.e., the side faces 228 of the casing 213, so thatthe linear guide 212 may be connected to any of the above surfaces orfaces.

The above-described pneumatic cylinder unit 201 of the presentembodiment, which is one obtained by fastening the attachment to thecasing 213 of the rodless cylinder 211, has a fastening structuresuitable for saving the installation spaces similarly to theabove-described first embodiment and is constituted so that rigidity isimproved. In addition, since the linear guide 212 is attached as anattachment, the reciprocating body 225 can be moved with high accuracywhen the reciprocating body 225 driven by the rodless cylinder 211 isguided by the linear guide 212.

FIG. 31 is a perspective view showing a modification example of theabove-described pneumatic cylinder unit 201 according to the tenthembodiment. In this pneumatic cylinder unit 241, the linear guides 212are disposed respectively on both sides of one rodless cylinder 211, andthey are directly fastened by the insertion fasteners 8, which areembedded in the respective T-shaped slots 229 and 239, similarly to thepneumatic cylinder unit 201 shown in FIG. 27. Therefore, a reciprocatingtable 235 a attached to the reciprocating body 225 can be linearlyreciprocated with higher accuracy since guided by two guide rails 233 onboth sides. Further, although not illustrated, as another modificationexample of the pneumatic cylinder unit employing the rodless cylinder,two rodless cylinders 211 in which the two rodless cylinders 211 aredirectly fastened using the insertion fasteners 8 may be formed.

Next, a pneumatic cylinder to which a rod cover provided with afunctional component corresponding to a use application is selectivelyattachable, and a pneumatic cylinder unit constituted by using thepneumatic cylinder will be described in the following eleventh tofourteenth embodiments.

FIG. 32 is a perspective view of an entirety of a pneumatic cylinderused in a pneumatic cylinder unit according to an eleventh embodiment ofthe present invention, wherein FIG. 32A is a perspective view showing anexploded state before assembling and FIG. 32B is a perspective viewshowing an assembled state. FIG. 33 is an axial-directionalcross-sectional view taken along line A-A of the assembled pneumaticcylinder of FIG. 32B.

In FIG. 32A, the pneumatic cylinder 301 a in an exploded state beforeassembling includes a rod cover 303 for discharging dusts and a basiccylinder 302, as individual assembly parts. The basic cylinder 302 has acylinder tube 305, whose both axial-directional end faces 304 aresubstantially square and whose entirety has an axially long cuboidshape, and is provided with a piston rod 306 protruding from a center ofone of the end faces (end face 304 on a front side of the Figures). Inaddition, screw holes 307 are formed at four corners of the same endface. Note that although the end faces 304 of the basic cylinder 302 aresubstantially square, they may be rectangular and the screw holes 307may be formed not at the four corners of the end face but at two cornerson a diagonal line thereof.

The rod cover 303 for discharging dusts has a rod cover 309 a formedinto a cuboid whose end face 308 has the same shape as that of thecylinder tube 305, and a later-described functional component isprovided to an interior thereof. A rod through hole into which thepiston rod 306 can be inserted and a bolt through hole 312 into which abolt 311 can be inserted are formed at a central position of the endface 308 and at each of the four corners or two corners on a diagonalline of the end face 308, respectively, so as to penetrate axially therod cover 309 a.

By inserting the piston rod 306 into the rod through hole 310 and beingfastened by four or two bolts 311 in a state of contacting serially withthe basic cylinder 302 and the rod cover 309 a, the pneumatic cylinder301 a as shown in FIG. 32B is assembled integrally.

In each of four side faces 313 of the pneumatic cylinder 301 aintegrally assembled thus, the communication groove 6 opened so as toextend linearly through the length in an axial direction and theengagement groove 7 communicating with it are formed. Feed/dischargeports 316 and 317 for feeding and discharging compressed air are formedat two locations overlapping the communication groove 6 in one side faceof the cylinder tube 305. A dust outlet 318 serving as an air dischargeport is formed at one location overlapping the communication groove 6 onone side face of the rod cover 309 a.

As shown in FIG. 33, a piston accommodating hole 319 is formed axiallyin an interior of the cylinder tube 305. A packing case 320 with whichthe rod cover 303 for discharging dusts is provided is fitted in anopening on a side on which the piston rod 306 protrudes. A head cover321 is provided at an end of the cylinder tube 305 located on anopposite side thereof. A space formed between the packing case 320 andthe head cover 321 of the piston accommodating hole 319 constitutes acylinder chamber 322. A piston 323 is attached to an interior of thecylinder chamber 322 so as to be reciprocable axially, and the piston323 divides the interior of the cylinder chamber 322 into a fluidpressure chamber 322 a for retraction and a fluid pressure chamber 322 bfor extension.

A rod bush 324 employing an oil-impregnated copper alloy as its materialis provided in the rod cover 309 a, and the piston rod 306 fixed to anend face of the piston 323 penetrates the packing case 320 and the rodbush 324 and slidably protrudes from the rod through hole 310.

The piston 323 is formed into a substantially cylindrical shape, whereinan outer diameter of an extension-side end 323 a and a retraction-sideend 323 c thereof is slightly smaller than that of a slide-intermediateportion 323 b therebetween and the slide-intermediate portion 323 b isfitted in and slidably contacts with the piston accommodating hole 319and the extension-side end 323 a and the retraction-side end 323 c formgaps with an inner circumferential surface of the piston accommodatinghole 319. A wear ring 323 d is attached to each outer periphery of theextension-side end 323 a and the retraction-side end 323 c so as tosandwich front and rear parts of the slide-intermediate portion 323 b.These wear rings 323 d are capable of reserving and maintaining thecommunication with the fluid pressure chamber 322 a for retraction andthe fluid pressure chamber 322 b for extension without blocking thefeed/discharge ports 316 and 317 even when each of the feed/dischargeports 316 and 317 coincides with the axial-directional position thereofin spite of slidably contacting with the piston housing hole 319.

The piston 323 is at an extension-side stroke end position in a state inwhich its extension-side end face contacts with the retraction-side endface of the packing case 320, and is at a retraction-side strokeend-position in a state in which the retraction-side end face of thepiston 323 contacts with the extension-side end face of the head cover321.

In a state in which the piston 323 is positioned at the extension-sidestroke end position, the feed/discharge port 316 communicating with thefluid pressure chamber 322 a for retraction is disposed at the sameaxial-directional position as that of the small-diameter extension-sideend face 323 a, so that the feed/discharge port 316 is not blocked bythe slide-intermediate portion 323 b of the piston 323 and thecommunication with the fluid pressure chamber 322 a for retraction canbe always ensured.

In a state in which the piston 323 is located at the retraction-sidestroke end position, the feed/discharge port 317 communicating with thefluid pressure chamber 322 b for extension is disposed at the sameaxial-directional position as that of the small-diameter retraction-sideend face 323 c, so that the feed/discharge port 317 is not blocked bythe slide-intermediate portion 323 b of the piston 323 and thecommunication with the fluid pressure chamber 322 b for extension can bealways ensured.

Packings 326 slidably contacting with the piston rods 306 are providedin a through hole 325 of the packing case 320 and a rod through hole 310of the rod cover 309 a. O rings 327 are provided on outer peripheries ofthe packing case 320 and the head cover 321, and a seal ring 328 isprovided on an outer periphery of the slide-intermediate portion 323 bof the piston 323.

In the rod bush 324, a dust passage 329 communicating with an outercircumferential surface of the piston rod 306 at the position near thepacking 326 which is attached to the rod through hole 310 is formed, andthis dust passage 329 communicates with the dust outlet 318 of the rodcover 309 a so that these constitute altogether a discharge passage.This discharge passage is a functional component provided in the rodcover 303 for discharging dusts. When an unshown air suction device etc.is connected to the discharge passage, dusts generated by slidablecontact between the piston rod 306 and the packing 326 can be dischargedthrough this discharge passage.

As described above, the pneumatic cylinder 301 a employed in thisembodiment serves as a double-acting pneumatic cylinder for driving anobject to be driven by controlling a supply of the compressed air toeach of the two feed/discharge ports 316 and 317 so as to reciprocatethe piston rod 306 in the straight-line direction, and has a structuresuitable for use in a process which requires high cleanliness, such as asemiconductor manufacturing line, since the dusts generated by linearreciprocation of the piston rod 306 are not emitted to an outersurrounding area.

In addition, the rod cover 303 for discharging dusts, which is providedwith the discharge passage serving as a functional component, can beattached to and detached from the basic cylinder 302 and arbitrarilyreplaced, so that even if failure occurs in either the dust dischargefunction of the rod cover 303 for discharging dusts or the rod drivefunction of the basic cylinder 302, this structure has high resourceefficiency since the one in which the failure occurs has only to bereplaced without changing the entirety.

Also in the above structured pneumatic cylinder 301 a, the communicationgrooves 6 and the engagement grooves 7 are formed on the side faces 313,so that by being fastened to the attachment (including cylinder tube)etc. forming the communication grooves 6 and engagement grooves 7 viathe insertion fasteners 8, whereby the pneumatic cylinder unit of thepresent embodiment can be formed. FIG. 34 is a perspective view of anentirety of a pneumatic cylinder unit of the present embodiment formedby fastening two pneumatic cylinders 301 a, wherein FIG. 34A is aperspective view showing an exploded state before assembling and FIG.34B is a perspective view showing an assembled state.

As shown in FIG. 34, in the two pneumatic cylinders 301 a, therespective piston rods 306 are arranged parallel in the same direction,the cylinder tubes 305 and the rod covers 309 a are made to contact witheach other by side faces 313 c and fastened via the insertion fasteners8, and a common tip plate 332 serving as a linking member for mutuallyconnecting both piston rods 306 is attached to the tips of the pistonrods 306 thereof, whereby a twin-rod cylinder is constituted. When thepneumatic cylinders 301 a are driven by air pressure, this tip plate 332drives the piston rods 306 in the straight-line direction, therebydriving the object to be driven in the straight-line direction by a tipface of the tip plate 332. In this structure, the two cylinder tubes 305to be fastened are mutually serving as attachments.

The pneumatic cylinder, which constitutes the above-mentioned pneumaticcylinder unit and to which the rod cover with a functional component isattachably and detachably provided, will include the following examples.

FIG. 35 is a perspective view of an entirety of a pneumatic cylinder 301b used in a pneumatic cylinder unit according to a twelfth embodiment ofthe present invention, wherein FIG. 35A is a perspective view showing anexploded state before assembling and FIG. 35B is a perspective viewshowing an assembled state. FIG. 36 is an axial-directionalcross-sectional view taken along line B-B of the pneumatic cylinder 301b assembled in FIG. 35B. In these Figures, members and shapes commonwith the pneumatic cylinder 301 a shown in FIGS. 32 and 33 are denotedby the same reference numerals.

In FIG. 35A, the pneumatic cylinder 301 b in an exploded state beforeassembling has a rod cover 341 for oil-impregnated bearing which isprovided with a later-described oil-impregnated bearing in an interiorof a rod cover 309 b, and the basic cylinder 302, as individual assemblyparts. A rod through hole 342 through which the piston rod 306 canpenetrate is formed at a center of the end face 308 of the rod cover 309b, so that by inserting the piston rod 306 into the rod through hole 342and being fastened by four bolts 311 in a state in which the basiccylinder 302 and the rod cover 309 b are made to serially contact witheach other, the pneumatic cylinder 301 b such as that shown in FIG. 35Bis assembled integrally.

As shown in FIG. 36, a housing 343 provided with the rod cover 341 foroil-impregnated bearing is fitted in an opening of the pistonaccommodating hole 319 on a side on which the piston rod 306 protrudes,whereby a space formed between the housing 343 of the pistonaccommodating hole 319 and the head cover 321 is forming the cylinderchamber 322.

The housing 343 is secured and installed in the interior of the rodcover 309 b by a seal holder 344 and a snap ring 345, whereby the pistonrod 306 penetrates the housing 343 so as to slidably protrude from therod cover 309 b. The piston 323 is at the extension-side stroke endposition in a state in which the extension-side end face thereofcontacts with the retraction-side end face of the housing 343.

The oil-impregnated bearing 346 to which lubricating oil is impregnatedis provided at a portion contacting with the outer circumferentialsurface of the piston rod 306 in the interior of the housing 343, andthe oil-impregnated bearing 346 constitutes a functional componentprovided in the rod cover 341 for oil-impregnated bearing. Since thisoil-impregnated bearing 346 contacts slidably with and supports thepiston rod 306, the piston rod 306 can be smoothly slid whilemaintaining the airtightness of the cylinder chamber 322.

As described above, the pneumatic cylinder 301 b employed in the presentembodiment serves as a double-acting pneumatic cylinder, and has astructure in which the piston rod 306 can be driven with high efficiencywith respect to supply pressure and supply amount of compressed air.

FIG. 37 is a perspective view of an entirety of a pneumatic cylinder 301c used in a pneumatic cylinder unit according to a thirteenth embodimentof the present invention, wherein FIG. 37A is a perspective view showingan exploded state before assembling and FIG. 37B is a perspective viewshowing an assembled state. FIG. 38 is an axial-directionalcross-sectional view taken along line C-C of the pneumatic cylinder 301c assembled in FIG. 37B. In these Figures, members and shapes commonwith the pneumatic cylinder 301 a shown in FIG. 32 and FIG. 33 aredenoted by the same reference numerals.

In FIG. 37A, the pneumatic cylinder 301 c which is in an exploded statebefore assembling has a ball-bearing rod cover 351 provided with alater-described ball bearing in the interior of the rod cover 309 c, andthe basic cylinder 302, as individual assembly parts. A rod through hole352, through which the piston rod 306 can penetrate, is formed at acenter of the end face 308 of the rod cover 309 c, so that by insertingthe piston rod 306 into the rod through hole 352 and being fastened byfour bolts 311 in a state in which the basic cylinder 302 and the rodcover 309 c are made to contact with each other, the pneumatic cylinder301 c such as that shown in FIG. 37B is assembled integrally.

As shown in FIG. 38, a sleeve 353 with which the ball-bearing rod cover351 is provided is fitted in an opening of the piston housing hole 319on the extension side of the piston rod 306, whereby a space formedbetween the sleeve 353 of the piston accommodating hole 319 and the headcover 321 constitutes the cylinder chamber 322.

The sleeve 353 is secured and installed in an interior of the rod cover309 c by a housing 354 for the packing 326, a seal holder 355, and asnap ring 356. The piston rod 306 penetrates the sleeve 353 and thehousing 354 so as to slidably protrude from the rod cover 309 c. Thepiston 323 is at the extension-side stroke end position in a state inwhich the extension-side end face thereof contacts with theretraction-side end face of the sleeve 353.

A large number of balls 357 contacting with the outer circumferentialsurface of the piston rod 306 for guiding the axial-directional movementof the piston rod 306 are installed in the sleeve 353, and a ballbearing 358 housing these balls 357 forms the sleeve 353, whereby afunctional component provided in the ball-bearing rod cover 351 isconstituted. Since the ball bearing 358 supports the piston rod 306, thepiston rod 306 can be smoothly slid while certainly supported also withrespect to a lateral direction.

As described above, the pneumatic cylinder 301 c employed in the presentembodiment serves as a double-acting pneumatic cylinder, and has astructure in which the piston rod 306 can be smoothly reciprocated whilea large lateral load applied thereon is tolerated.

FIG. 39 is a perspective view of an entirety of a pneumatic cylinder 301d used in a pneumatic cylinder unit according to a fourteenth embodimentof the present invention, wherein FIG. 39A is a perspective view showingan exploded state before assembling and FIG. 39B is a perspective viewshowing an assembled state. FIG. 40 is an axial-directionalcross-sectional view taken along line D-D of the pneumatic cylinder 301d assembled in FIG. 39B, wherein FIG. 40A is a cross-sectional viewshowing a state in which a movable stopper is at an extendable limitposition and FIG. 40B is a cross-sectional view showing a state in whichthe movable stopper is at a retractable limit position. In theseFigures, members and shapes common with the pneumatic cylinder 301 ashown in FIGS. 32 and 33 are denoted by the same reference numerals.

In FIG. 39A, the pneumatic cylinder 301 d, which is in an exploded statebefore assembling, has a rod cover 361 for stroke adjustment which isprovided with a later-described movable stopper in an interior of therod cover 309 d, and the basic cylinder 302, as individual assemblyparts. A rotating knob 362 a with a shape of a circular plate isattached to a central position of the end face 308 of the rod cover 309d and further a rod through hole 363, through which the piston rod 306can penetrate, is formed at the central position. By inserting thepiston rod 306 into the rod through hole 363 and being fastened by thefour bolts 311 in a state in which the basic cylinder 302 and the rodcover 309 d are made to serially contact with each other, the pneumaticcylinder 301 d such as that shown in FIG. 39B is assembled integrally.

As shown in FIG. 40, the movable stopper 364 a, with which the rod cover361 for stroke adjustment is provided, is fitted in the opening of thepiston accommodating hole 319 on a side on which the piston rod 306protrudes, and a space formed between the movable stopper 364 a of thepiston accommodating hole 319 and the head cover 321 constitute thecylinder chamber 322.

A stopper accommodating hole 365 a, which is concentric with and has thesame diameter as that of the piston accommodating hole 319, is formed inthe rod cover 309 d, and the movable stopper 364 a is screwed in afemale screw 366 formed on an extension-side inner periphery of thestopper accommodating hole 365. When rotating about its central axis,the movable stopper 364 a is screwed so as to axially move forward orbackward. The piston 323 is at the extension-side stroke end position ina state in which the extension-side end face thereof contacts with theretraction-side end face of the movable stopper 364 a, and is at theretraction side stroke end position in a state in which theretraction-side end face of the piston 323 contacts with theextension-side end face of the head cover 321.

In addition, in the extension-side end face of the rod cover 309 d, aretention groove 367 is formed along a circle disposed on an slightlyouter circumferential side of and being concentric with the opening ofthe stopper accommodating hole 365 a, and further a securing groove 368is formed in a side wall on the outer circumferential side.

On the retraction-side end face of the rotating knob 362 a, acylindrical portion 369 b whose tip is provided with a flange 369 acapable of being fitted in the retention groove 367 is formed. Since asnap ring 370 is fitted into an outer periphery of the cylindricalportion 369 b and the cylindrical portion 369 b is press-inserted intothe retention groove 367, the snap ring 370 is engaged with the securinggroove 368 therein and the entirety of the rotating knob 362 a isrotatably attached to the rod cover 309 d. The piston rod 306 penetratesthe movable stopper 364 a and the rotating knob 362 a and slidablyprotrudes from the rod cover 309 d.

On the retraction-side end face of the rotating knob 362 a, rotationtransmission pins 371 are provided so as to protrude at two positionsaround the rod through hole 363 regarded as the center, and rotationtransmission holes 372 are formed at two positions corresponding to theextension-side end face of the movable stopper 364 a so that therespective rotation transmission pins 371 are slidably inserted therein.

As shown in FIG. 40B, in a state in which the movable stopper 364 a isat a fully retracted position, a screw hole 373 is formed at the sameaxial-directional position as that of the extension-side end thereof onan upper surface of the rod cover 309 d in the Figure, and a stoppersetscrew 374 is screw-connected to an interior thereof.

Also, in a state in which the movable stopper 364 a is at the nearestposition to the retraction side, the feed/discharge port 316communicating with the fluid pressure chamber 322 a for retraction isdisposed at the same axial-directional position as that of a chamferedportion 375 formed on the outer periphery of the retraction-side endface thereof, whereby even when the movable stopper 364 a is at theretractable limit position, the communication from the feed/dischargeport 316 to the fluid pressure chamber 322 a for retraction is ensured.

An axial-directional length “Z” of the extension-side end 323 a of thepiston 323 with a small diameter is almost equal to a movable length “Y”(stroke adjustment width) of the movable stopper 364 a, so that evenwhen the movable stopper 364 a is at the extendable limit position andthe piston 323 is at the extension-side stroke end position, thefeed/discharge port 316 is not blocked by the slide-intermediate portion323 b of the piston 323 and the communication with the fluid pressurechamber 322 a for retraction is always ensured.

In addition, the O ring 327 is provided on the outer periphery of themovable stopper 364 a, and the packing 326 is provided in a through hole376 of the movable stopper 364 a. In the above-described structure, themovable stopper 364 a contacts with the piston 323 so as to constitute astopper for restricting the stroke end position of the piston 323, therotating knob 362 a and the rotation transmission pin 371 constitute aposition adjustment member for adjusting the position of the movablestopper 364 a, and the entire mechanism in the rod cover 361 for strokeadjustment including those described above constitute an assembly forstroke adjustment serving as a functional component.

Next, an operation of the pneumatic cylinder 301 d will be explained.First, as shown in FIG. 40A, in a state in which the movable stopper 364a is at the extendable limit position, the extension-side stroke endposition of the piston 323 is at the fully extended position and theaxial-directional length of the cylinder chamber 322, i.e., the movementstroke of the piston 323 becomes the longest one.

When the rotating knob 4 is rotated in this state, the movable stopper364 a is also rotated via the two rotation transmission pins 371 and, asa result, the movable stopper 364 a is screwed so as to move backward.In executing this movement, although the movable stopper 364 asimultaneously gets away from the rotating knob 362 a, the rotationtransmission pins 371 fixed to the rotating knob 362 a maintain statesof slidably contacting with and being inserted into the rotationtransmission holes 372 of the movable stopper 364 a. Therefore, therotating knob 362 a keeps transmitting the rotation to the movablestopper 364 a. Thus, when the movable stopper 364 a moves backward, theaxial-directional position of the retraction-side end face thereof,i.e., the extension-side stroke end position of the piston 323 is alsoretracted and accordingly a movement stroke of the piston 323 alsobecomes shorter.

As described above, the pneumatic cylinder 301 d employed in the presentembodiment serves as a double-acting pneumatic cylinder, wherein theextension-side stroke end position and the movement stroke of the piston323 can be adjusted by rotating the rotating knob 362 a and changing theaxial-directional position of the movable stopper 364 a. In addition,even when the above-described adjustment is being made, the total lengthof the fixed portions, which includes the rotating knob 362 a, the rodcover 309 d, and the cylinder tube 305, is not changed and therefore canbe installed even in an axially narrow space. Moreover, the movablestopper 364 a can be fixed by tightening the stopper setscrew 374.

FIG. 41 is an axial-directional cross-sectional view of a pneumaticcylinder 301 e provided with a modification example of theabove-described rod cover for stroke adjustment 361. In FIG. 41, memberscommon with the pneumatic cylinder 301 d shown in FIG. 40 are denoted bythe same reference numerals.

As shown in FIG. 41, a securing groove 377 is formed in anextension-side inner periphery of a stopper accommodating hole 365 b. Acylindrical portion 378 a which can be fitted into the stopperaccommodating hole 365 b is formed in a retraction-side end face of arotating knob 362 b. When the snap ring 370 is fitted into a securinggroove 378 b formed in the outer periphery of the cylindrical portion378 a and the cylindrical portion 378 a is press-inserted into thestopper accommodating hole 365 b, the snap ring 370 is engaged with boththe securing groove 378 b in a side of the cylindrical portion 378 a andthe securing groove 377 in a side of the stopper accommodating hole 365b, whereby the entirety of the rotating knob 362 b is rotatably attachedto a rod cover 309 e. A female screw 379 with a diameter larger thanthat of the piston rod 306 is formed in a center of the rotating knob362 b, whereby an extension-side part of the movable stopper 364 b isscrew-connected to the interior thereof and a retraction-side partthereof is slidably attached to the piston accommodating hole 319 andthe stopper accommodating hole 365 b. A rotation prevention groove 380is axially formed on an upper side face of the movable stopper 364 b inthe Figure, and a stopper setscrew 382 serving as a rotation preventionmember is screw-connected to a screw hole 381 formed in an upper endface of the rod cover 309 e in the Figure so as to be engaged with therotation prevention groove 380.

According to this modification example, the movable stopper 364 b canmove only axially without being rotated about the axis due to theengagement with the stopper setscrew 382 and therefore, by rotating therotating knob 362 b, can be certainly screwed so as to axially moveforward or backward.

Therefore, similarly to the pneumatic cylinder 301 d shown in FIG. 40,the extension-side stroke end position and the movement stroke of thepiston 323 can be adjusted by changing the axial-directional position ofthe movable stopper 364 b. Moreover, the movable stopper 364 b can befixed by tightening the stopper setscrew 382.

As described above in the eleventh to fourteenth embodiments, thepneumatic cylinders 301 a to 301 e have highly versatile structurescapable of corresponding to various applications are provided, since therod covers 309 a to 309 e equipped with functional componentscorresponding to use applications can be selectively attached to thebasic cylinder 302 provided in common as a main driving unit.Accordingly, also in terms of designing and manufacturing, thefunctional components which are prepared in many types depending on theuse applications can be provided as component parts which areindependent from driving performance of the basic cylinder 302.Therefore, there is obtained also advantage of being capable of avoidingmultiplication of types of product cylinders by virtue of such acombination and simplifying production management.

The present invention is not limited to the above-described embodimentsand can be variously modified without departing from the gist thereof.For example, although the above-described embodiments have shown onlythe case where the sectional shapes of the engagement grooves 7 and theengaging pieces 11 are formed to be rectangular, they are not limitedthereto as long as each of them is formed to have a width larger thanthe opening width “Wo” of the communication groove 6 and the fasteningsurfaces 15 and the engagement surfaces 9 contact certainly with eachother. For example, they may have a polygonal shape as shown in FIG. 42or a half circular shape as shown in FIG. 43. Moreover, as long as thefastening surfaces 15 and the engagement surfaces 9 can certainlyface-contact with each other, these are not limited to that formed to beparallel with the connection surfaces 3 c. For example, they may beformed to be inclined with respect to the connection surfaces 3 c asshown in FIG. 44.

Alternatively, the communication groove 6 and the engagement groove 7 donot require being formed throughout the entire length in thelongitudinal direction of the member to be fastened, and may be cut at amiddle position, bent at a middle position, curved in whole, or formedpartially at a middle position of the connection surface. In such cases,the intermediate fasteners 71 and 73, as shown in FIGS. 12 and 13, whichcan be installed at the longitudinal-directional intermediate position,can be suitably utilized.

In addition, although the fasteners in the fastening assemblies of theabove-described second to sixth embodiments are formed as metal-fittingswhich are metal-made molded products, they may be resin-made moldedproducts.

In addition, regarding the guide units serving as attachments, thenumber thereof to be fastened can be arbitrarily set by being increasedor reduced as required, and the tip plates may be also arbitrarilyformed and installed according to the number and arrangement of rods.

Further, although the rodless cylinder 211 employed in the pneumaticcylinder unit of the tenth embodiment is a slit type, another type ofrodless cylinder such as a magnetic type can be also applied.

Also, although the cases where the functional components comprise thedust discharging channel, the oil-impregnated bearing, the ball bearing,and the assembly for stroke adjustment in the pneumatic cylindersemployed in the pneumatic cylinder units of the above-described eleventhto fourteenth embodiments have been described, structures other thanthese can be applied to the functional components.

In addition, in the above-described embodiments, the pneumatic cylindersemploying the compressed air as the working fluid are shown as examplesof the fluid pressure cylinder, but the present invention is not limitedthereto and, for example, can be applied to that employing a liquid asworking fluid such as oil hydraulic.

INDUSTRIAL APPLICABILITY

The fastening assembly and the fastener according to the presentinvention can be applied to any fastening structure in which therespective surfaces of two members are made to contact with each otherand fastened therebetween, and particularly are useful in application tothe cases where easy and reliable fastening is required and where spacesaving is required in a fastened state and to a fastening structure inwhich arbitrary and easy setting and change of the relative arrangementbetween the two members and the fastening position are required.

Further, the fluid pressure cylinder unit according to the presentinvention is particularly useful in the case where space saving isrequired and, at the same time, an attachment etc. has to be fastened inorder to realize enhancement of rigidity and highly accuratereciprocation, such as an actuator employed in a device for conveyingelectronic components such as semiconductor chips.

1. A fastening assembly comprising: two members, on each of which aconnection surface is formed and which a communication groove extendingand opened in a longitudinal direction along each of said connectionsurfaces, and an engagement groove provided with an engagement surfaceparallel with each of said connection surfaces and communicating withsaid communication groove are formed; and a fastener including, in astate in which said communication grooves are opposed to each other andsaid two members are made to contact through each of said connectionsurfaces, a first engaging piece whose fastening surface is formed inthe longitudinal direction and which is inserted into said engagementgroove of one of said members in the longitudinal direction, a secondengaging piece whose fastening surface is opposed to said fasteningsurface and formed in the longitudinal direction and which is insertedinto said engagement groove of the other of said members in thelongitudinal direction, and a connecting portion which has a widthsmaller than those of said engaging pieces and at whose base end each ofthe engaging pieces are connected, wherein when said fastener isembedded in said two members and said engagement surfaces and saidfastening surfaces contact with each other, said two members areconnected.
 2. The fastening assembly according to claim 1, wherein saidengagement grooves, said first engaging piece, and said second engagingpiece are formed to become wider than said communication groove.
 3. Thefastening assembly according to claim 1, wherein said fastener is anintermediate fastener which is installed at a longitudinal-directionalmiddle position of said communication groove and said engagement groove.4. The fastening assembly according to claim 3, wherein said connectingportion is formed into a cylindrical shape with a diameter capable ofbeing inserted into said communication groove, and a width in a state inwhich at least one of said first engaging piece and said second engagingpiece is rotated about a central axis of said connecting portion by apredetermined angle is formed smaller than the width of saidcommunication groove.
 5. A fastener for fastening two members, thefastener comprising: a first engaging piece whose fastening surface isformed in a longitudinal direction; a second engaging piece whosefastening surface is opposed to said fastening surface and formed in thelongitudinal direction; a connecting portion having a width smaller thanthose of said engaging pieces and connecting the engaging pieces at abase end; and a fastening member for elastically deforming tips of saidengaging pieces in a direction in which the respective fasteningsurfaces approach each other.
 6. The fastener according to claim 5,wherein said fastening member is a screw member, which penetrates anouter surface parallel to said fastening surfaces and a tip face of saidengaging piece, so as to be screw-connected to a screw hole formed insaid engaging piece.
 7. The fastener according to claim 5, furthercomprising a cut-in portion formed for dividing respective tips of saidengaging pieces into an outer elastically deformable portion and aninner elastically deformable portion, wherein said fastening portion isa screw member to be screwed into a screw hole formed between said outerelastically deformable portion and said inner elastically deformableportion.
 8. The fastener according to claim 5, wherein said fasteningmember is formed by a fastening piece in which an abutting face abuttingon an abutting face formed to be inclined is formed at each tip of saidengaging pieces and by a screw member to be screw-connected to a screwhole formed in said fastening piece, through a through hole formed insaid connecting portion.
 9. A fastener for connecting two members, thefastener comprising: a first engaging piece integrally provided with afirst connecting portion, and having a fastening surface wider than saidfirst connecting portion and formed in a longitudinal direction and anabutting face formed so as to be inclined at a tip thereof; a secondengaging piece integrally provided with a second connecting portion, andhaving a fastening surface wider than said second connecting portion andshifted in the longitudinal direction from and mutually opposed to saidfastening surface and formed in the longitudinal direction, and a secondengaging piece having an abutting face abutting on said abutting faceand formed at a tip thereof; and a screw member screw-connected to ascrew hole formed in one of said engaging pieces, penetrating a throughhole formed in the other of said engaging piece with a diameter largerthan that of said screw hole, and making said engaging pieces move alongsaid abutting face in a direction in which the respective fasteningsurfaces approach each other.
 10. A fluid pressure cylinder unit fordriving an object to be driven in a straight-line direction by a fluidpressure, the unit comprising: a cylinder tube, in which a communicationgroove extending and opened in a longitudinal direction along aconnection surface and an engagement groove provided with an engagementsurface parallel to said connection surface and communicating with saidcommunication groove are formed and a piston provided with a piston rodis accommodated axially and reciprocably; an attachment, in which acommunication groove extending and opened in the longitudinal directionalong a connection surface contacting with said connection surface andan engagement groove provided with an engagement surface parallel tosaid connection surface and communicating with said communication grooveare formed; and a fastener including, in a state in which saidcommunication grooves are opposed to each other and said cylinder tubeand said attachment are made to contact by said connection surfaces, afirst engaging piece whose fastening surface is formed in thelongitudinal direction and which is inserted into said engagement grooveof said cylinder tube in the longitudinal direction, a second engagingpiece whose fastening surface is opposed to said fastening surface andformed in the longitudinal direction and which is inserted into saidengagement groove of said attachment in the longitudinal direction, anda connecting portion having a width smaller than those of said engagingpieces and connecting each of said engaging pieces at a base endthereof, wherein when said fastener is embedded in said cylinder tubeand said attachment and said engagement surfaces and said fasteningsurfaces contact with one another, said cylinder tube and saidattachment are connected.
 11. The fluid pressure cylinder unit accordingto claim 10, further comprising a fastening member for elasticallydeforming tips of said engaging pieces in a direction in which therespective fastening surfaces approach each other.
 12. The fluidpressure cylinder unit according to claim 10, wherein a transversesection of said cylinder tube is a quadrangle, and respective mutuallyadjacent outer circumferential surfaces thereof serve as connectionsurfaces in which said communication grooves are formed.
 13. The fluidpressure cylinder unit according to claim 10, wherein said attachment isa cylinder tube similar to said cylinder tube.
 14. The fluid pressurecylinder unit according to claim 13, wherein a piston rod of saidcylinder tube and a piston rod of said attachment are connected by aconnecting member.
 15. The fluid pressure cylinder unit according toclaim 13, wherein said two cylinder tubes are fastened so thatrespective piston rods thereof are directed in reveres to each other,and a chuck member is attached to each of said piston rods.
 16. Thefluid pressure cylinder unit according to claim 13, wherein a guide railis attached to each of said cylinder tubes, and a slide table attachedto a sliding body which slides along said guide rail is connected toeach of said piston rods.
 17. The fluid pressure cylinder unit accordingto claim 10, wherein said attachment serves as a guide block for axiallyaccommodating a guide rod reciprocably, and said guide rod and saidpiston rod are connected by a connecting member.
 18. The fluid pressurecylinder unit according to claim 17, wherein a plurality of saidcylinder tubes and a plurality of said attachments are fastened,respectively.
 19. A fluid pressure cylinder unit employing a rodlesscylinder for driving a reciprocating body in a straight-line directionby fluid pressure, the unit comprising: a casing of the rodless cylinderin which a piston reciprocated in the straight-line direction by thefluid pressure and connected to said reciprocating body is incorporatedand in which a communication groove extending and opened along aconnection surface formed at an outer periphery and an engagement groovecommunicating with said communication groove and being wider than saidcommunication groove are formed; an attachment in which a communicationgroove extending and opened along a connection surface contacting withsaid connection surface and an engagement groove communicating with saidcommunication groove and being wider than said communication groove areformed; and a fastener including, in a state in which the respectivecommunication grooves are opposed to each other and said casing and saidattachment are made to contact respectively by said connection surfaces,a first engaging piece inserted into said engagement groove of saidcasing in a longitudinal direction, a second engaging piece insertedinto said engagement groove of said attachment in the longitudinaldirection, and a connecting portion for connecting those engagingpieces, the fastener being embedded in said casing and said attachment.20. The fluid pressure cylinder unit according to claim 19, furthercomprising a fastening member provided to said fastener for applying afastening force to said casing and said attachment via said fastener.21. The fluid pressure cylinder unit according to claim 19, furthercomprising: a piston yoke protruding, through a slit formed in areciprocation guide surface formed in said casing, outwardly from saidreciprocation guide surface and connecting said piston and saidreciprocating body; an inner sealing band fixed to both ends of saidcasing and sealing said slit from inside; and an outer sealing bandfixed to the both ends of said casing and sealing said slit fromoutside.
 22. The fluid pressure cylinder unit according to claim 19,wherein said attachment is a guide member provided with a rail forguiding said table.
 23. The fluid pressure cylinder unit according toclaim 22, wherein guide members are fastened on both sides of the casingof said rodless cylinder.
 24. The fluid pressure cylinder unit accordingto claim 19, wherein said attachment is a casing of a rodless cylinderof the same type as that of said casing.
 25. A fluid pressure cylinderunit for driving an object to be driven in a straight-line direction byfluid pressure, the unit comprising: a cylinder tube for accommodating apiston; a piston rod attached to said piston and protruding from an endface of said cylinder tube to outside; and a rod cover mountedattachably and detachably on the end face of said cylinder tube, whereinsaid rod cover is provided with a functional component exhibiting afunctional effect in accordance with a use application.
 26. The fluidpressure cylinder unit according to claim 25, wherein a communicationgroove extending and opened in a longitudinal direction along aconnection surface and an engagement groove provided with an engagementsurface parallel to said connection surface and communicating with saidcommunication groove are formed in said cylindrical tube, there areincluded: an attachment in which a communication groove extending andopened in the longitudinal direction along a connection surfacecontacting with said connection surface and an engagement groove havingan engagement surface parallel to said connection surface andcommunicating with said communication groove are formed; and, a fastenerprovided with, in a state in which the respective communication groovesare opposed to each other and said cylinder tube and said attachment aremade to contact respectively by said connection surfaces, a firstengaging piece whose fastening surface is formed in the longitudinaldirection and which is inserted into said engagement groove of saidcylinder tube in the longitudinal direction, a second engaging piecewhose fastening surface is opposed to said fastening surface and isformed in the longitudinal direction and which is inserted into saidengagement groove of said attachment in the longitudinal direction, anda connecting portion having a width smaller than those of said engagingpieces and connecting the respective engaging pieces at a base endthereof, and when said fastener is embedded in said cylinder tube andsaid attachment and said engagement surfaces and said fastening surfacesare made to contact with one another, said cylinder tube and saidattachment are connected.
 27. The fluid pressure cylinder unit accordingto claim 25, wherein said functional component is a discharge passage,which is connected to a discharge port formed in said rod cover anddischarges, to the outside, a dust generated by linear reciprocation ofsaid piston in said fluid pressure cylinder unit.
 28. The fluid pressurecylinder unit according to claim 25, wherein said functional componentis an oil-impregnated bearing incorporated in said rod cover andcontacting with an outer circumferential surface of said piston rod. 29.The fluid pressure cylinder unit according to claim 25, wherein saidfunctional component is a linear ball bearing incorporated in said rodcover, contacting with a outer circumferential surface of said pistonrod, and having a ball for guiding axial-directional movement of saidpiston rod.
 30. The fluid pressure cylinder unit according to claim 25,wherein said functional component is an assembly for stroke adjustment,which has a stopper incorporated in said rod cover and restricting astroke end position of said piston by contacting with said piston and aposition adjustment member attached to said rod cover and adjusting aposition of said stopper.
 31. The fluid pressure cylinder unit accordingto claim 25, wherein any of a rod cover for discharging dusts providedwith said discharging passage, a rod cover for oil-impregnated bearingprovided with said oil-impregnated bearing, a linear-ball-bearing rodcover provided with said linear ball bearing, and a rod cover for strokeadjustment provided with said assembly for stroke adjustment can beattached to the end face of said cylinder tube.
 32. The fluid pressurecylinder unit according to claim 25, further comprising a fasteningmember provided to said fastener and applying a fastening force to saidcylinder tube and said attachment via said fastener.